If I would start over I would do the following:
* have at least 10 customers willing to buy my service when it's done. During the time of development they would commit to spend time with me validating my product hypothesis.
* prepare spec for a _REAL_ mvp.
* clearly _describe_ problem that I'm trying to solve. (now I know that it takes multiple iterations to achieve this - most importantly discussing the problem with your future customers)