My thoughts on the James Gunn situation- there's no 100% right or wrong option, however Disney KNEW James Gunn said those things, they KNEW he apologized in 2012 and he's done no similar actions or tweets since. The Disney knee-jerk reaction of immediately firing him was the worst part of that.
Will Disney get rid of any Seth MacFarlane shows when they take over Fox, because he's made some pretty awful comments ON his actual TV shows that could be construed badly. It's called shock humor and there used to be a time where we could accept it for what it is and not read too far into it. Yes, what James Gunn said was horrific, but that was the point! That was the kind of industry he was in with Troma at the time.
Using the same situation, I don't think Roseanne should have been fired, but given some "cool off" time to make up for it. I'm in no way a fan of hers, but she's been making shock humor for years also.
I mean, I watched Top Gear and now The Grand Tour with Jeremy Clarkson who has said some horrible things as well, but I'm still a fan of his and don't think he'd ever really harm someone.
For Disney/Marvel this is a really bad situation because the MCU has been such a cash cow and Guardians has been a huge part of that. I think they should have given James Gunn a different role, maybe just as a producer/consultant, but use the same script and not allow him to direct the film. Something of a compromise, but that ship has sailed I fear.