Stuff like that is likely - but here it would completely be breaking the story IMO. Many things wouldn't make a lot of sense. It'd be probably easier to have Sasha and/or Bree be your real life sisters (from a story change perspective, not a modding one).
Yes you can. After you show her the proof of Ryan cheating on her, wait a couple of days, and go visit her at the bakery. She will ask you to go on a date where you can choose to have her as a girlfriend or stay as friends. However, I do not remember if turning her down makes her leave the game.
Technically by the strict definition of the tag right now: no.
Well, there certainly are some consequences, you can lose girls if you act wrongly, or lock yourself out from parts of the story. However, part of sandbox stat collecting games is that you can get a point you missed on monday back on thursday and the game will not change otherwise. Completely branching paths is very difficult in this as opposed to more linear visual novels because you may have to have dozens if not hundreds of ways a certain scene plays out depending on how you played before that. E. g. if you want your work environment to change if you collared (some of) the girls, it's already 16 different possibilities.
Sasha blowing her ex, you need to not advance her like score too fast though.
But enough to piss off the haters
A term I saw in another thread is "NTReeees." I guess based upon their shrill shriek.
For racing Hannah, you need to ask her on a date on Saturday or Sunday afternoon, and take her to the park.
