I want him not to be Iago both because I like him and because it's more exciting if there's another, deeper player who's moving all the pieces rather than some tiny, petty little conspiracy made of actors who should know better (I mean Sabat himself is probably as popular and famous as Vic anyway, so there's no reason for him to be jealous). I don't think he's Iago because he's too obvious, but we'll see. I can't wait for discovery so we can start getting new info, rather than just confirming old info in bits and pieces.
That said, yes, even if he's Iago, I do expect him to be someone who will flip if he sees the ship sinking. But how hilarious would it be if he were never Iago, and all this time he was on Vic's side but had to pretend not to be lest his career be targeted? After all, Nick did say Monica would cry if she ever found out who the mole(s) was.