I actually don't have a lot that I specifically want to get out of a rewrite, apart from Bruce being more in character -- I just don't see him blindly following Tony's lead when he knows what a truly bad idea it is for them to tap into that alien tech for Ultron, even if the science is exciting. His entire schtick is about how his life was ruined because he wasn't more circumspect, thus making him righteously paranoid. And, of course, I want to avoid the entire Nat business.