There are positives and negatives about my situation:
+ no risk for my family (except I am very busy)
+ I can actually experiment my product at my current jov (kind of customer 0)
+ my employer (large european corporation not in the IT business) was actually surprisingly willing to let me work on a side project, and did not bother me with IP.
- So far, I did not manage a single real customer (though company only started 2 months ago). I may have a better result if I was full time.