1) Cheating doesn't make him not a feminist.
2) If that leaked WW script is really his, combined with the gender stuff from Avengers, Firefly, etc, then I could say that makes him not a feminist.
3) Having sex with women over whom he has professional authority is hugely problematic. I can look the other way once or twice if there's no quid pro quo (feelings happen, desire happens), but habitually, or any sniff of it being for favor, that can't pass.
4) There's more than a little discussion in this thread that strikes me of the "women can't consent to sex" type, which I had thought was long past its due date. But someone at work was using it recently, so shrug, I guess.
5) I don't know what Whedon has said in this letter people referenced, but I'm really really not inclined to believe an ex-spouse about the specifics on a partner's cheating.
6) Did she really say she has ptsd from his cheating? If so, I think that's enormously disrespectful to people who have been through real trauma.
7) Last week I found out a young woman over whom I had authority complained to my supervisor that I DIDN'T flirt with her. Sex and power are a lot more complicated than some are treating it here.