Don't ask yourself multiple questions. Ask a potential customer ONE question: "Will you give me $10 or 10 minutes to be on my early access list for a product XYZ that solves your pain ABC?"

This tells you a few things:

1) Is there an identifiable customer and do you know what they look like and how to reach them?

2) Do they have a pain bad enough they know what you were referring to and cared enough to listen?

3) Did they care enough about solving that pain to do something nominal like giving you $10 to be on a special beta list (or whatever)?