That sucks that you have to look for someone new during such a stressful time. From what you wrote, I would definitely ask how long it usually takes his office to get back to patients who call in crisis and other scenarios.

I suppose it is always good to ask how much experience they have with bipolar disorder (and your type) and their general treatment approach. How open are they to suggestions about medications from patients? If you like one or all of your meds, are they willing to keep it/them, or would their first step be to overhaul?