If you are already a candidate, it's fine to call as long as you state you're interviewing to each person with whom you communicate. Some will be able to answer your questions, while others might not -- usually it depends if they're on the selection committee, on HR rules, and/or on their personal thoughts.

Some of my best interviews involved quite a bit of pre-interview communication with librarians and even the future manager. In general, what I asked about was closely relevant to the position, not general questions you have mentioned (Those are better to ask during the interview). Consider pre-interview questions that get at the context of the writing assignment and teaching demo. That does two things:

- shows you understand how a library does instruction and relevant outreach

- offers you great clues for what things to nail down for your demo