You cannot work more than 38 hours because then you become full time and they will fire you for that.
What tips or advice would you give to someone interviewing at Michigan State University?
All that you can really do is present yourself to the best of your ability. MSU HR departments range from finicky and picky to laid back and almost flagrant, so for all you know, your shoe color could have stopped you from getting the job. Different departments want different things, so try to visit the departments first to see what the general "air" of the place is before applying.