You have to do what makes writing the story most enjoyable for you. That might be leaving GA out of it. Send him on a mission or something. If you try to be nice, the hypocrisy you feel may make the story an unpleasant experience. If you have other characters snark at him, it might make the story difficult because you're writing in a way you don't like.

I know, I'm with you on your dislike. I never liked GA, not even in comic books. Oliver is the one character I thing SV didn't actually screw up, because he's been screwed up long before the show. I hope you can figure out what to do.

As to the other, I'd say the same thing. Write them the way you think fits the story best, or you won't enjoy writing it.