Cnut -
It's perfectly normal and very sweet of you to be worried! As far as hazing etc, the horror stories you hear are the exception, not the rule.
I started dating a senior when I was a freshman, and pledged my 1st semester sophomore year (after he graduated). After I joined the sorority, I broke up with my boyfriend. Now that your heart is in your mouth
it's not because I pledged, it was because of his ATTITUDE towards my pledging. He was totally resentful that I was doing something without him, disliked all the sisters, and told his friends in fraternities (he was not in one) to "keep an eye" on me. If he would have tried harder to understand I needed this, I would have tried harder to maintain the relationship. With the way he acted, I didn't want to try.
It was a revelation to me to find out that I didn't have to be tethered to a man to have fun, I could just have fun with my sisters. It helped me to become more of a "whole" person and has probably enhanced every relationship I have had since joining. One of my sisters said to me "We came in as girlfriends and left as people." That was about the size of it.
You both need to get involved at your different campuses, whether it's Greeks, sports or whatever. You owe it to each other and your relationship to keep growing and changing and not just staying together out of habit. You won't be that far apart and there will probably be a lot of visiting. I know you have probably heard this a zillion times but it's true - if it's meant to be it will be.