TBSG -- I would definately say to go for it. You seem to really really want this, and I agree with everyone when they say if you don't, you'll always wonder "what if".
I have only been through informal rush, but to be honest, at the beginning, I wasn't really sure if I really wanted to. Now I am sooooooo happy I did, because I absolutely love all the girls here!!
And I know if I didn't go through with it, I would have wondered "what if" after college was over.
You seem very devoted to this, and I think any sorority would lucky to have such a devoted member.
Best of luck!