Your phrasing is what I noticed. "Catching" MC? MC wasn't hiding shit (if purely on a Bella path, at least). She saw them, she didn't 'catch' them. The phrasing implies they are doing something illicit. They're both adults, and they're fucking each others' brains out throughout her house, and then Jill just walks away. I love the shocked look on her face.
Granted, it plays out very slightly differently if you're pursuing Jill as well, in which case, well.. you get what you deserve? Jill certainly looks angry later on if you were chasing them both beforehand.
The update is the 8.1 update to the 8.0 release only, there is no official update from episode 7 to 8.
Quinn is not a main girl, only the main girls get separate entries. Quinn is a side girl, and thus 'others'.
Physically, I have liked her since the start, but when she attacked MC over Jamie getting his ass kicked, she crossed the line from 'cute' to 'fuck that uppity bitch'. I didn't get Jamie's ass kicked, Dawe is just a sucker-punching bitch. (#FUCKYOUDAWE ?) Seeing her absolutely retarded mentality in episode 8 (non-binary bunny?) solidified her as one of the first I'll throw on the funeral pyre with no remorse. Right after Linda.
Based on what I've seen in the past pages of this thread, it looks like you tried to apply the update patch to episode 7, which is not going to work. The update was for 8 to 8.1, not from 7 to 8. The only official way to get the whole game is to download the whole game for episode 8 (there is an unofficial 7-8 update somewhere in the thread). The error you are getting is because you don't have the full game resources, so it can't load them.