Don'r make statements, anything that starts "this more a statement than a question" isn't helpful to anyone.
Pay attention to previous questions, just because you didn't like the answer, rephrase or expand, don't just ask the same again.
Accept these people (candidates) are mostly enthusiastic amateurs they will not have much expert knowledge on your pet topic (the history of the local band stand) as you will, don't make this about point scoring. Ask genuine questions that can either be answered or an opinion given.