Very few people are qualified at the outset to found & start a company... Yet people pull it off every day.
The secret is that we can learn and grow along with our company.
You've received a huge number of responses here because wrestling with how to build a product is an art - and that means experience.
Bias yourself to gaining your own experience, not to worrying about the optimality of your approach to product development - and that means, ironically, *knowing* you're going to make mistakes with your product.
Ship it, baby... just ship it. Not because it's necessarily right for the product, but because it is absolutely right for you at this stage. Come back to this thread and post why shipping early was an awful idea if you have to- but come back with that experience sooner rather than later.
The secret to building a startup is that you have to build yourself up as you build your product. Get out there, have people berate you, have people ignore you, fall on your face... but keep shipping.
You'll get there - and the faster you go, the sooner you'll arrive.