Well, I just finished playing the game, not long ago, skipped Alexis story entirely and went for Layla (Oh dear God... Layla and Elena, those two... I can't get enough of them) while playing goody 2 shoes mode, and want to re-play it, now with Alexis plot, so that is on my to do list.
Regarding Zack and that little bitch of Ethan... they can eat a Komatsu 930E load of dicks, fucking pieces of shit, I hope for an abrupt and harsh ending for them, so we can enjoy the game properly
Whereas a lot of players here want a harem type of ending, quite probably it won't go like that, and highly possible either you will be forced out of some relationships or will be lead to choose a girl over another.