Yeah, all very good points. Just one of those situations where I don't care about these characters. I don't actively dislike them just feel like I'd rather spend time with other characters but the narrative is focused more on them than anyone else. I want to see the MC actually having to make choices and solidifying his actual interests in an individual (or the throuple) versus meaningless sex and being spread out among all of the potential love interests.Some people are like that, though. There are people who are like an open book and are very open with others, even complete strangers, and there are some who are more closed-off and trying to get them to open up is like trying to draw blood from a stone. People also have their reasons for not wanting to tell others certain things about themselves, and sometimes those reasons can be quite understandable and sometimes they're not, but it's not really up to us to judge them based on how we would behave and deal with such things as everyone is different and deals with things in their own way, whether it's the objectively right or wrong way to go about it.
Everyone in this story has caught feelings pretty fast, including Sage, Jill, and Bella; it's just the way these VNs are, even ones that are bit better written like this one. But there is such a concept of love at first sight, so being instantly drawn to someone and inexplicably developing deep feelings for them in a short space of time is not that far-fetched of a concept. The majority of LIs are also very late teens to early 20s and at that age things can develop quickly like this because hormones are still raging and can result in more intense feelings.
As for M&J's happiness, that's doubtful even on the friend/rejection path. Again, at that age things often seem bigger and more serious than they generally are and so the issue with Maya's Dad and the fear of judgement from others still weighs heavily on their relationship, and now they also have the added tension of Quinn and the tuition money for Maya. So a lot of strain is still going to be put on their relationship, in addition to the fact that they are both still clearly harbouring feelings for the MC which means their minds will not be solely focused on each other when they're together.
And the whole "harbouring feelings" thing, I find it ridiculous considering it has been only two weeks. The idea that those feelings are so intense that they could possibly destroy their established relationship but at the same time they don't want to define their relationship with the MC in a way that would require him to be exclusive to them is