What questions should a customer ask to hire the right service professional?
Are you licenced & insured? This above all is the most important question. It does not matter how experienced the professional, without a licence their is no cover for defective work. This is your best chance for quality assurance.
What makes your pricing competitive?
The quality attached to the price.
What questions do customers commonly ask and how would you answer them?
How much will it cost? There is on one answer to this question as every job and client or even tradesperson is different. The more information you can give your tradesperson the better your quotation/estimation will be.