As for my preference for the LI's;
Sage - Hot, no strings attached (As yet) redhead who is therefore the most honest and open one with you. That's why (putting aside the porn) I enjoy her scenes as you actually tend to learn stuff from her.
Josey - In story terms I've known her the longest and before things got very complicated. I also like her 'chipper' attitude as it translates to the kind of girls I liked in RL.
Bella - Is growing on me since I explored her route more but she still scares me with her unblinking ways and her hot or stone cold swings.
Jill - Is a very well modelled character but she's the kind of girl that I find deeply, deeply boring.
Maya - Don't trust her and (as mentioned before) her less then a week swing from 100% lesbian to wanting to be your/my girl makes me think she's a little unbalanced. I like a touch of crazy from time to time but seeing as she's Dereks sister and I'm potentially trapped in proximity to her for 4 years.........I wanna keep that at arms length.
Sage - I think is sweetheart at heart, but she's heavily concerned about hierarchy and what people think from the outside, vain. But she's changing because of the MC
Josy - she's more confident, she's definitely has DIK in her, and I mean her attitude, I think eventually she will have a DIK route ending with he MC, just my opinion.
Bella - Her story has a lot of layers to it. I think her mood swings as you put are understandable, her parents died when she was relatively young, her relationship with her husband is clearly not that good. And she's unsure how she's supposed to feel with the MC, she clearly enjoys being around him, but she's torn because she's married and because of Jill, and probably also because of the age difference and she's a teacher.
Jill - She's clearly the cannon path, she mirrors the relationship that the MC's parents had. But she is also clearly a sweetheart as well, she tries to make the MC laugh when he's having a bad day.
Maya - Yes she wasn't a 100% honest, but it's realistic, we gotta remember these are mostly teenagers, it's very uncommon for a teenager to have all their shit together. I think Maya has a pretty submissive personality, and she can be swayed by a more dominant personality like Josy and the MC, which is also scary because Quinn is a more dominant personality. But Maya isn't some shitty person.