2. This also differs. In both situations when I was hired, I told them when I would give them the answer, they didn't give me a deadline. I told both I needed 48 hours to discuss with family and work out logistics (moves were involved). Any longer and you're messing with other candidates and personnel issues, which I don't care for. Now, on the other side of the table, I've had people back out on jobs they've verbally accepted weeks later...so I'd rather you take 3 or 4 days to give me an answer than to take the job and back out the Friday before summer band starts.
I will say that most admin I've worked with realize it may take longer for someone to decide if there is a move involved, you need to communicate that, though. Tell them you are definitely interested but you need a few days to work out logistics before committing. Tell them when you'll let them know, and don't miss the deadline. You can call earlier if needed.