friends

Knowing people in a sorority definitely does give you some leverage because they know your name, they can vouch for your reputation, and they can sort of "pull" you in. But having friends in a house does not guarantee a bid. I had a friend in PM and I was dropped right after IWTs. And my freshman year roommate had multiple friends in ADPi and she got dropped after Philanthropy.

Having friends doesn't help you too much unless you have multiple in one house and y'all are best friends.

Having friends can help or hurt you, sometimes that friend thinks you're not a good fit for their house

It depends how well-respected your friends are in their house. They are the ones who have to fight for you. There are a few girls in my house whose opinions about people I would absolutely not trust.

Maybe.
Maybe not.
If a sorority already has 300 Birmingham girls who are artistic fashion merchandising majors, and you're from Vestavia and you're majoring in fashion merchandising, you may be out of luck. They may be looking for engineering majors from Huntsville. Or looking to diversify by pledging more OOS.
It just depends. Your friends will also be only a handful of the 300 current members.