Most awkward gig nights are not caused by anyone behaving badly. They are caused by two sides assuming different things and neither of them checking. The fix is a short list of questions, sent before you confirm, while it is still easy to say "actually, that will not work for us".
Cancellation is the question people skip because it feels pessimistic to raise. It is the one that causes the most bad feeling later. Asking it early is not distrust — it is the same instinct that makes you check the load-in time.
You are not being difficult by asking. A venue that programmes music regularly has answered all of this before and will have the answers to hand.
Not a drip of individual questions over a week. One short message, grouped like the lists above, is quicker for the venue to answer and makes you easy to deal with — which is a large part of getting asked back.
If you are approaching rooms you have not played, their listing is the place to start: look them up and see what they already tell you, so you only ask what is genuinely missing.