What to do about overzealous friend?

My friend 'Stacy' and I may attend the same college this coming fall, but I have a few problems she refuses to acknowledge.

1) As soon as we get there (we will be freshmen) she wants us to get an apartment off campus and let her dead beat boyfriend move in with us. (He treats her terribly and keep keep a decent job. She's also falling into the trail of money problems and I don't want to be stuck with a full rent that was supposed to be split.).

2) She's completely hung up on the idea that we WILL be roommates one way or another. (I simply suggested the college because of her then-desired major of graphic design).

3) Our friendship is entirely superficial and we didn't speak hardly ever until our senior year. We don't even have decent conversations unless I say something remotely related to college or she tries to talk crap about my best friend.

I honestly don't know how to broach the subject. We are two totally different people and I've exhausted nine tenths of my energy trying to talk to her. Do you all have any suggestions?
What to do about overzealous friend?
Post Opinion