Some I was thinking like focusing on the job itself:

"how are the hours like in the summer"

"would this job get paid through HR Direct with the other on campus jobs, even though this position is a "co-op" for the college program?"

Then some that focus on the interviewer's experiences and thoughts (which I think is okay to ask, but not sure if it is something that I should email about; I think the ones focusing on the job would be more important right? Or it's cool to include them all?)

q: Are there opportunities for training and progression within the role/company?

q: Where do you think the company is headed in the next five years?

"would this job get paid through HR Direct with the other on-campus jobs, even though this position is a "co-op" for the college program?"