Yeah it was Felicity who heavily updated Olivers systems and turned into a High tech HQ^^ (Interestingly enough Chloe did the very same thing with the Watchtower HQ of the Justice League on Smallville - a team that was founded by Oliver in Season 6) She even got him a state of the art compound bow, which he has been using ever since. Barry later also created an actual mask for Oliver, like he has in the comics, which he is wearing now under his hood.
The "Torturer" you are referring too was wearing a similar mask, but it was yellow-black instead of red-black. Actually this caused many too believe at first that this guy was Deathstroke until it was released that it wasnt Slade under that mask. The man under the yellow-black mask was Billy Wintergreen, who in the comics was a sidekick for Slade for years until they had a fallout and Slade killed him.
On Arrow Slades background was changed a bit and he and Billy are both australian (in the comics Slade is american) and were working for ASIS (australian intelligence). They were members of an elite team known as Team 7 (That team actually exists in the comics as well but as a special forces team of the US government) that were sent to the island to rescue Yao Fei. However Eddie Fyers and his mercenaries killed the members of the team except for Slade and Billy. Billy joined Fyers as his enforcer while Slade escaped. All members of Team 7 have such a mask (though in different colors), thats why both Billy and Slade have one. Billy then later tortured Oliver on Fyers command and as you probably remember eventually Slade and Billy faced off and Slade killed Billy by stabbing him in the eye (which was an ironic reference to Slade having only one eye in the comics). Another nice reference was when Slade finds a sword in Season 2 and says "I like swords". That is a reference to Slade using swords as his signature weapons in the comics.
Slade also mentioned that Billy was the godfather of his son Joe. In the comics Slade had actually three children. There was Grant, who was later killed when a mission that Slade was on went wrong and for years Slade felt guilty about his death. Then there is Joseph Wilson (Thats most likely his son Joe that he is referring to in Arrow) who later become the supervillain Jericho, who hated his father and vowed to destroy him. Slade later killed him in battle. His third child is his daughter Rose Wilson, who at first became the assassin Ravager who was trained by Slade but later joined the superheroteam Teen Titans and developed a hatred towards her father. They reconciled later though and because of his love for his daughter, Slade went more from villain to anti-hero (but also still an assassin), making him an increasingly more complex character. I wonder if we´ll ever see Joe, Grant or Rose on Arrow.
As for Olivers story on Smallville:
as a teenager he went to a prep school in england together with Lex Luthor. During those days Oliver was pretty arrogant and cruel and bullied Lex often, which eventually even led to the death of a classmate. This was a wake up call for Oliver who changed completely after that.
"My hands are far from clean. But I have been trying to wash them ever since while yours just kept getting dirtier"
-Oliver to Lex in the present
Soon afterwards Olivers parents Robert and Laura Queen were murdered by Lionel Luthor (the Queens were part of a secret society called "Veritas" whose purpose it was to protect the kryptonian Kal-El after his arrival on earth and help to guide him to his destiny of becoming Superman, but Lionel who was also a member betrayed the group because he wanted Kal-El for himself), leading to Oliver cutting himself from emotions and becoming a party-loving playboy. After he graduated he went on a cruise onboard a yacht, but the yacht was attacked by pirates and sunk. Oliver was the only survivor and made it to an island.
Here over the course of two years, he learned to survive and taught himself to hunt with bow and arrow. Two years later he was poisoned and kidnapped on the island by mercenaries, which is where he met Tess Mercer (who was also a prisoner). She cured him and together they escaped their captors and used their ship to escape the island.
Oliver and Tess went to Star City where they were together for a while but after he cheated on her and she left him, Oliver felt unworthy of his parents legacy and joined a secret organisation of Assassins where he was trained by the Dark Archer (Malcolm Merlyn is Arrows version of the Dark Archer), which is where he learned his superior archery skills. However Oliver left the Organisation because of their extreme views and methods (This is extremely similar to Saras story in Arrow Season 2). In Season 9 his former mentor comes to Metropolis to challenge Oliver to a final duel. Oliver wins (with Clarks help) but doesnt kill him..
Afterwards Oliver returns to Star City and decides to honor his families memory by using his new skills to protect Star City from evil and injustice and creates himself a disguise in form of a green costume to protect his true identity. He also takes over his families company and becomes the CEO of Queen Industries. After the events at the beginning of Smallville Season 6 (where the evil kryptonian General Zod takes over the body of Lex and nearly destroy the world), Oliver moves to Metropolis to investigate this further after he hears that Lex (controlled by Zod) was seen breaking into the Pentagon, having enormous superhuman powers.
This is where Oliver meets Lois Lane (and through her he also meets Clark Kent) and the two fall deeply in love. He begins patrolling the streets of Metropolis in his disguise and its Lois (who doesnt know its Oliver) who eventually names him Green Arrow. Clark finds out that Oliver is Arrow and helps protect his secret. During this Oliver also finds out what Clark can do and that he is actually an alien from the planet Krypton. Oliver deeply admires Clark, not just for his powers but his enormous goodness and convictions and aspires to be more like him but at the same time he also advises Clark that with that kind of power he should be out there protecting people, making the world a better place.
"There is a whole world of people out there, Clark. You cannot wait for them to come to you. When you´re ready to do something about that, you know where to find me" - Oliver to Clark
Oliver also meets other remarkable people with special powers. The first of those is Bart Allen (who comes from the future and is actually Barry Allens grandson and also has the same ability as the Flash) who joins Oliver and becomes the costumed superhero Impulse. Bart is also a very close friend of Clarks, who sacrifices himself for him in the Season 11 comic series.
Ollie and Bart then meet Victor Stone, a man who once had a terrible car accident and whose ****tered bones were replaced with bionic body parts by Lex in order to create a super soldier. Victor escaped Lex with Clarks help. He joins Oliver and Bart and becomes the superhero Cyborg. Later the three of them save a man named Arthur Curry at the coast of Japan. Arthur was trying to stop some whale catchers but was captured by them and nearly killed. Arthur is actually an atlantean and heir of the throne of the underwater kingdom Atlantis (though he only finds out about that some years later) and as an atlantean has special powers. He can breathe underwater, move with superhuman speed under water and has superhuman strength while his body is wet (even more increased under water). he also can communicate with any animals living in water. he joins Oliver and his team, becoming the superhero Aquaman.
In the Season 6 episode "Justice" Oliver assembles this team (which is basically the prototype version of the future Justice League) for the first time onscreen to take down a facility of Lex Luthor, in which he uses kryptonite to experiment on people. Clark joins them for this mission as well (being dubbed "Boy Scout" by Oliver). While Clark afterwards isnt ready to join Olivers team just yet on their missions, he says that one day he will.
CYBORG: What about you? We could use the big guns.
AQUAMAN: yeah you gotta come with us, man.
OLIVER: They´re right you know. You´d be a major asset to the team.
CLARK: I wanna be part of this guys, I really do. But there are some things I need to figure out and take care of first.
OLIVER: This isnt the end of the story, Clark. This is just the beginning.
In Season 7, Oliver and Clark meet Dinah Laurel Lance aka the Black Canary who later joins the team as well. Starting with Season 8 the evolution of the team into the Justice League is explored in more detail. Chloe (Olivers future wife) becomes the operator of the team, codename Watchtower and she is the one setting up the high tech HQ (also called Watchtower) for the team in metropolis. By the time of the Season 11 comic series, the team actually has headquarters (or Hubs) in every major city in the US.
In Season 8 the team is joined by the martian John Jones (who used to be an ally of Clarks birth father Jor-El and has watched over Clark for years). As a martian he has incredible superpowers that rival Supermans (superstrength, superspeed, flight, can blast energy from his eyes, shapeshifter, can make himself intangible, powerful telepath) and becomes the superhero "Martian Manhunter". Oliver also meets the beautiful sorceress Zatanna in Season 8 who joins his team as well.
In Season 9 the team meets the surviving members of the "Justice Society of America" (JSA), a superheroteam from the 70s who were forced into exile by the US-government when they refused to work for them. the JSA was actually the first superheroteam in comics history (created in 1940). The former JSA members Hawkman (who becomes a close friend with Clark but has a rivalry with Oliver) and Stargirl eventually join Olivers team (By this time Clark is also already a superhero known as "The Blur" and has joined the team in full). Hawkman later sacrifices himself in Season 10 to save Clarks love, Lois Lane.
Another former JSA member, Jay Garrick (the first Flash) later in the Season 11 comic series forms the previously mentioned superheroteam Teen Titans, consisting of the following members:
Conner Kent/SUPERBOY
a clone from the genes of Clark and Lex. He has similar powers to Clark but if he is exposed to red kryptonite his "Lex" side is unleashed and he becomes evil. He becomes romantically involved with Miss Martian. He is introduced in Season 10.
Mia Dearden/SPEEDY
A former prostitute and protege of Oliver and Black canary. Like Oliver she is an archer. She was introduced in Season 9.
Jaime Reyes/BLUE BEETLE
A young teenager, that an alien high tech scarab device attached itself to. the device allows Jaime to call upon a blue alien armor to encase his body and giving him superhuman strength, flight and energy projection. he was introduced in Season 10.
Zan & Jayna/WONDER TWINS
Two siblings with superhuman powers. Zan can turn himself into all forms of water and ice and Jayna can shape**** into any animal she desires. However they need to bump their fists together to activate their powers. They greatly idolize Clark and want nothing more then to be true heroes. they were introduced in Season 9.
Morgan Gann/MISS MARTIAN
besides John Jones (who is her mentor), she is the last surviving martian and the last living white martian (John is a green martian). she was trapped for years and became out of control until John and Batman found her and were able to restore her senses. She becomes romantically involved with Superboy. She is the only member of the team who wasnt introduced on the TV show but in the Season 11 series.
In Season 10, Clark met the superhero Booster Gold, a self-loving former athlete from the 25th century who stole a high tech suit and travelled to the 21st century to become the worlds greatest hero before Clark could become Superman. He eventually learned from Clark that the suit doesnt make the hero and learned the value of being a real hero. He stayed in the 21st century and joined Clarks and Olivers team. he became much more mature in Season 11 after he travelled with Superman to the 31st century and fought in a war between humans and kryptonians.
In the Season 11 comic series the show was able to introduce some heroes who joined the team that they were not able to use on the TV-show, such as Batman and Wonder Woman (the two biggest superheroes in the DC Universe besides Superman). It also expected that the Flash (Barry Allen) and Green Lantern will soon be introduced on the Season 11 series (which is currently ongoing)
Although Batman and Wonder Woman are of course characters you know, here is a bit about how they are in ther Smallville versions:
Bruce Wayne/BATMAN
A billionaire and CEO of Wayne Tech, who witnessed the murder of his parents at a young age, forever scarring him emotionally and making him grim and vengeful. He is raised by his butler and friend Alfred Pennyworth and once out of school trains his body and mind to the peak of human perfection becoming the worlds greatest detective, a genius, master tactician, criminal psychologist and martial arts expert. He dons a bat-themed costume, becoming the Batman and begins fighting a war against organized crime in his home Gotham City utilizing his superior skills, intimidation, fear and various state of the art equipment and vehicles. he starts his career as Batman already in 2001 (at a time where Clark was only just starting highschool) and until Season 11 he is actually thought by many to be a mere myth (until he meets Superman and Green Arrow). In season 11 he also has a sidekick, the spunky Barbara Gordon (who is the original Batgirl in normal comics) who is named Nightwing in the SV version. It is shown that Oliver is incredibly jealous of Batman, because Batman is very similar to him but superior to Ollie in almost every way. When Lois and Chloe enter the Batcave for the first time Chloe says "Okay, now I understand why Ollie is so jealous"
Diana Prince/WONDER WOMAN
Diana is the daughter of Queen Hippolyta, queen of the Amazons of greek myth and was born and raised on the mythological paradise island known as Themyscira. She is also the biological daughter of Zeus, the reigning olympian deity of greek mythology and therefore a demigod. 20 years ago a boy named Steve Trevor stranded on the island and he and Diana became close friends and once teenagers developed a crush on each other. After Hippolyta found out about it she decided to take Steve back to "Mans world" - only she and Steve never came back. Once she was an adult, Diana left the island to search for her mother, eventually coming to Washington DC. here she not only met Superman and Lois Lane but also her old flame Steve who was now working for a government organisation known as the DEO. the leader of the DEO was actually working for the greek deity Hades and was trying to free him from the Underworld. Diana discovered that the DEO held her mother captive (which Steve didnt know) and with the help of Superman found and rescued her mother. However the leader of the DEO was subsequently able to free Hades, who assaulted washington with an army of harpies and turned the Washington monument into a giant stone creature that nearly killed Superman. Diana donned her mothers amazonian armor, becoming the superhero Wonder Woman and aided Superman in the battle against Hades and his creatures. Together they were able to send Hades back to the underworld and save the US President. This brought great change to the world since the existence of magic, gods and mythological creatures was now revealed to the world and Superman later also revealed to the world that he was actually an alien from the planet Krypton to ease the worlds fear of these new discoveries. Diana decided to stay in Washington with Steve and protect "Mans world" as Wonder Woman, joining Clarks and Olivers team and creating herself the human identity of Diana Prince. After Steve became the new leader of the DEO, Diana joined the organisation as special agent as well to be at Steves side.
Here a listing plus images of the Superheroes in the Smallville-Version of the Justice League:
Clark Kent (Kal-EL)/SUPERMAN
First Appearance: Episode 001 "Pilot" (as Clark), Episode 175 "Savior" (as The Blur), Episode 218 "Finale" (as Superman)
Played by: Tom Welling
Powers: Superstrength, Superspeed, Invulnerability, Heat Vision, X-ray Vision, Microscopic/Telescopic Vision, Super Breath, Freeze Breath, Super Hearing, Flight
Special Weakness: Kryptonite, Magic
Bart Allen/IMPULSE *Deceased*
First Appearance: Episode 071 "Run" (as Bart), Episode 121 "Justice" (as Impulse)
Played by: Kyle Gallner
Powers: able to move with the speed of light by using the Speed Force (Power Source of The Flash)
Arthur Curry (Orin)/AQUAMAN
First Appearance: Episode 092 "Aqua" (as Arthur), Episode 121 "Justice" (as Aquaman)
Played by: Alan Ritchson
Powers: can breathe underwater, superhuman speed under water, superhuman strength (when skin is wet), commands animals of the oceans
Special Weakness: Heat
Victor Stone/CYBORG
First Appearance: Episode 103 "Cyborg" (as Victor), Episode 121 "Justice" (as Cyborg)
Played by: Lee Thompson-Young
Powers: Superhuman strength and durability (thanks to bionic body parts), can access every computer and electronical system once he connects to it
Oliver Queen/GREEN ARROW
First Appearance: Episode 111 "Sneeze" (as Oliver), Episode 114 "Arrow" (as Green Arrow)
Played by: Justin Hartley
Powers: Highly trained in martial arts, Master Archer, uses a variety of gadgets and trick arrows
John Jones (Jonn Jonnzz)/MARTIAN MANHUNTER
First Appearance: Episode 118 "Static" (Cameo), Episode 122 "Labyrinth"
Played by: Phil Morris
Powers: Superstrength, Superspeed, Shapeshifter, can make himself intangible, Flight, powerful telepath, Martian Vision
Special Weakness: Fire
Kara Zor-El/SUPERGIRL
First Appearance: Episode 133 "Bizarro" (as Kara), Episode 199 "Supergirl" (as Supergirl)
Played by: Laura Vandervoort
Powers: Same as Superman (see above)
Special Weakness: Kryptonite, Magic
Dinah Laurel Lance/BLACK CANARY
First Appearance: Episode 143 "Siren"
Played by: Alaina Huffman
Powers: Highly skilled in martial arts and knife fighting, uses throwing knifes, can produce the "Canary Cry" which ****ters glass and metal
ZATANNA ZATARA
First Appearance: Episode 169 "Hex"
Played by: Serinda Swan
Powers: Master of magic, casts magical spells by saying them backwards
Carter Hall/HAWKMAN *deceased*
First Appearance: Episode 187 "Absolute Justice"
Played by: Michael Shanks
Powers: highly trained in close combat and archaic weaponry, has artificial wings that enable him to fly at superhuman speed, some time after he and his great love (Hawkgirl) die, they are both reincarnated in an endless cycle of life, death and rebirth
Courteney Whitmore/STARGIRL
First Appearance: Episode 187 "Absolute Justice"
Played by: Britt Irvin
Powers: highly athletic, trained in martial arts, wields a magical staff that can project energy and teleport her
Michael Jon Carter/BOOSTER GOLD
First Appearance: Episode 214 "Booster"
Played by: Eric Martsolf
Powers: High tech suit and gadgets that give him Flight, superhuman strength, Energy projection and the ability to time travel
Bruce Wayne/BATMAN
First Appearance: Episode 220 "Detective" (Comics)
Powers: body and mind trained to peak of human perfection, master martial artist, master tactician, genius-level intellect, uses a variety of state of the art gadgets and vehicles, supreme criminal psychologist and the worlds greatest detective
Diana Prince/WONDER WOMAN
First Appearance: Episode 225 "Olympus" (Comics)
Powers: highly trained warrior, proficient with bladed weapons, indestructible magic lasso, indestructible bracelets, tiara that can be used as a throwing weapon (even cuts a kryptonians skin), superhuman strength, speed, agility and durability, Flight
