"1) We were not end users of our product. Dog fooding felt like a chore"

This may have affected your motivation. Its easier to stay motivated when you build a product you want to use. You know this already since its your #1 point.

You can learn marketing by reading books on branding, advertising and marketing. Learning Python/Django for an MVP is also great. Combine that with plan B. But you know the situation better than anyone.