Managing brokers are used to inquiries by people still in real estate school, so don't fret about the interview. At this point, you probably don't have any idea of what to expect or what to ask, so go ahead and tell them that! They'll probably be just fine leading the interview.
The most important thing (IMO) is that you feel comfortable in the office and with the managing broker. You're going to need help your first few months, so a good rapport with the boss (or other trainer-type person) is critical.
Regarding intervieiwng, I would wait until you're almost finished with school.
I have a blog on Active Rain called "Some thoughts on choosing your office" that might help.
http://activerain.com/blogsview/34237/First-Things-First-SomeGood luck!
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Jennifer Allan, GRI
RE/MAX Hall of Fame
Author of
Sell with Soul, Creating an Extraordinary Career in Real Estate without Losing Your Friends, Your Principles or Your Self-Respect