what determines the first round of cuts?

Yes, with all that you do have a good chance. Also 10 minutes isn't long but it's more than enough time to pick up a girl's vibe and make a first impression, usually an active can tell if a girl will fit in or not after a convo of that length

first you're cut automatically if you don't meet gpa requirements. then, after that, the active will rate you using whatever point system their sorority has. The top 500 girls (i'm just making up numbers) with the highest points comes back the next round. Every sorority on this campus has a point/grading system. Its a number game

Tbh it's known if you're going to be cut or not before you even step in the house and you will 100% be able to tell. Usually alumns go through the pnms throughout the summer and just cut anyone who isn't meeting the gpa requirement or girls who don't have recs. If your lucky and a house sees your resume and picture and really think you'd be a good fit theyll find you a rec but it's rare. And remember just because you have a 3.2 doesn't mean you're meeting that specific houses gpa requirement. There are also girls who have gpas as high as a 3.9 and end up with 5 houses after the first round of cuts. You're literally just a number to them at the beginning unless you have some major connections so don't take it personal.