I'm not knowledgeable about the impact on your dad's credit, but I am curious as to how you screwed up your credit so badly by your sophomore year in college. It doesn't seem fair that he would have to have a low-level worry going on all the time, wondering if his scores will tank if you mess up again. Can he take out the loan in his name, and you two set up a very formal, written-out plan where you pay him? If you have been careless with repayment in your short past, I don't know that you've had much time to change this behavior.
Just about everyone on this forum got here because our past actions caused problems for us (plus there are some people who had major medical disasters, etc.) We're all kind of muddling through, cleaning up our own messes as we go, and my personal belief is that it's not fair to endanger another person's credit until you've been doing things right for a substantial period of time. If you had thought of this as a means of improving your credit, there are a lot of other ways out there. Just a thought.
PS--If I ever have scores like 827's, I'd be just like your mom!
Think of your dad's situation --if something went wrong, he'd be hearing those "I told you so's" for a good long while... Welcome to the Tough Love credit forums. (Can you tell, I'm another mom? LOL)
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007