1. As many others have said, this series has been better-than-average at playing with usual harem romcom tropes, so hopefully this won't drag on too long.
2. As annoying as "psycho manhating lesbians obsessed with FMC" are in any medium and any story, did y'all forget this is a school with 1:359 boy-to-girl student ratio?
I'm actually surprised there aren't more violent misandrist Hanako-fangirls threatening MC to "stay the fuck away from her, you insignificant male specimen".
3. 100% chance she joins MC's harem (like there was ever any doubt), though still holding strong feelings for Hanako-oneesama.