As I see it, every LI or SG was written with inherent red flags and problems. I like that, it creates tension, drama, and waifu wars.
The fact that we are well into a casual relationship with V at the beginning, and us not having 'shot straight' is exactly the point, though it was clear that it started as a casual relationship.
I agree about the problems you pointed out, and I alluded to them. The students especially, I found problematic in terms of professional ethics, the yuckiness of the age difference, the power dynamics, etc.
Aside from being dangerously nuts, the only girl without dangerous ethical or moral issues is Kris, who has her own problematic red flags (though I still think that threesome with Alexa was mind blowing, especially when you take the Dom route).
It's clear from their history that Allison and MC are not compatible as a couple. They're "great in a crisis" but shit otherwise. I ended up with the best route for her, and am glad that it improves their relationship, but making the same mistake twice doesn't seem good. Being good coparents is great. I really don't want to risk that improvement by fucking up the relationship again.