Four questions that feel productive and are not.
"Do you think it's a good idea?" — They are not qualified to answer, and they will say yes. You have asked them to review your ego.
"Would you buy a product that did X?" — A hypothetical purchase from a hypothetical person. The answer is free to give and costs nothing to break.
"How much would you pay for X?" — People are poor at pricing things that do not exist. What they say and what their card does are different.
"Would you pay [price] for a product that did Y?" — The same hypothetical wearing a precise number, which makes it feel like rigour. A price agreed to in conversation is not a price anybody has paid. Ask instead what they pay today for whatever they use now.
"What would your dream product do?" — Sort of acceptable, but only as a way into why. The feature list you get back is a wish, not a requirement. Follow it with "why would that matter?" or you have collected fiction.
Every one of these can be repaired by pointing it at the past instead of the future.