Yeah, the stuff with Cassidy is pretty dub-con turning into a case of Stockholme Syndrome as her story progresses. And the first sexvent with Palla in the locker room is pretty dubious, too, as I for one am not so sure if she actually wanted to get fucked by the MC at that point. The collaring in general is aside from Cassidy consensual, though, so there isn't much of an issue there.
As for Gwendoline, she's a pretty bitchy side character and an ex of Anna, who is one of these women who say 'all men are trash' (I think this was an actual thing she says), and she's pretty mean to Anna on top of that. I think that she actually threatened to beat one of them or both of them, and that's essentially what triggers that threat of the MC beating her up. Regardless, this threat is issued after Gwendoline insults and bullys Anna, so I don't see
that much of an issue there, either.
Honestly, the one point where I really say that the MC is not that good a person is (aside from the stuff with Cassidy and that first encounter with Palla) his constant cheating if you try and play
all the girls

even if it's kinda redeemed by the fact that if you play your cards right, it does lead to the harems.
On a sidenote, why the everloving fuck is Kylie even in this game? I swear, she's simply
the worst.