For a lot of these questions so far you have to take into consideration that the person you are asking needs to look like they know what the answer is - but in reality might not give you the real answer. Some examples:
Q: do you have change control?
A: yes, we use RT
Real answer: we have RT and only the previous administrator used it and and we haven't touched it in 3 months.
Q: do you have daily backups?
A: yes, we use HP Data Protector.
Real answer: Since all our users storage is on a SAN and have snapshots we use previous versions to do day-to-day restores. We HOPE our daily backups actually run and if they miss something we'd never know until we start asking you where the backups are for
I think that the most important things you can do are:
Ask to meet your peers/subordinates. Not in an interview room but can you go see where they work and spend some time seeing what the day-to-day is like.
Ask what the company expects and provides for professional development.
Ask the interview and the peers/subordinate how often the company updates/upgrades/introduces new technology. The differences in answers can be enlightening.