Be aware that S1 arrow is quite different to the entire rest of the DCTV universe. They went for a grittier "Nolan Batman" style take on things but really his murderous rampage is not justifiable hero-stuff
. Though to be fair, I think they do a good job in-story later of explaining his psychology when he started out as a vigilante (and also why he later commits to a "only when there's no choice" philosophy over a "lol arrow for YOU arrow for YOU arrow for YOU too!" attitude)