Yeah, this is all going to be relationship-based. You can do the market based rent and have of utilities thing for a regular roommate, but with the relationship and the adjustments and commitments one makes to each other based on said relationship add another dimension to the question.

If you don't have it already, make sure you get your emergency fund of three months of expenses set up before you go ham on the loans. That way, you won't be scrambling when your car inevitably breaks down or you get laid off etc. Once you have that minimal amount of emergency fund, then you can go ham on the loans and get them knocked out.

You should be fine. Might not be super free with money until the loans are knocked out, butt you should be living decently.