1. You could get a part time job and pay the sorority expenses.
2. You can go to a formal with your sisters. One year a bunch of our sisters went without dates. It was a lot less expensive than buying two tickets.
3. Maybe. I didn't know anyone when I rushed, but I knew a few people who rushed when I was a sister. It didn't make much of a difference. BTW, they became sisters.
4. It's good to learn the background of each sorority...as long as you don't look like a sorority stalker.
5. I think that doing any type of charity, philanthropy, volunteer work will be viewed favorably by most sororities.
Good luck and Enjoy!