Personally, I feel that wearing a suit would be overkill. A nice pair or shoes, dress pants, long sleeve shirt (no button down collar) and a tie would be just right. The deal with corporate aviation is all about how you are on a long trip. You can't just fly with a guy and have an issue with them and them not see them again for years. You fly together ALL the time. You have to be easy going and be easy to get along with.

I wouldnt worry about technical questions. Just be yourself and relax

Good luck!