7. Be assured that OO, as a syntax, does not markedly influence performance at runtime, so runtime performance should not inhibit you. On the other hand, remember that no class is better than a bad class. So if you are not sure, do not 'class'.
8. Use DBC. I did not in my first application and that is about the only thing I regret. I have not used Data environments yet. Everything that has to with tables (dbf) in FPD is applicable to VFP.
9. Hang in there! Much of the guesswork is called 'the learning curve'. There is a solution to what you are trying to do. You just did not take enough time to figure out how.
10. My first application took double the time that I planned. But is also much better than I thought.

>to be continued ...