How much work-life balance should I expect to have as a Professorial Assistant at Michigan State University?

This is entirely dependent on your class schedule, eagerness to learn or contribute, and flexibility of the lab you are working in. Some PA's spend the minimal amount of time required to be in the lab to recieve a paycheck every other week. I have spent more than the required amount and have been rewarded with trust and respect from other members of the lab. I would advise to be clear that you are commited, but do not sacrifice academics for the sake of your job. Also, make sure to communicate when you need time to catch up in a class or study for exams.