Heya! Thanks for the useful set of questioning.
I hadn't seen earthtojake/text-to-cad, looks cool I'll have to check it out. I approached creating printy to solve the problem of friends and family wanting me to print "something" for them, but them not knowing CAD or how to search thingiverse or whatever.
The other reason was, I like to do woodwork or other physical maker hobbies, but going and trying to hack something together in tinkercad to use in my project would end up burning hours I could have been building.
Ideally, printytron solves those.
I've been doing some work on file types recently - I'm hoping to give more support for different types, to allow you to do exactly what your describing. Do you have any specific file types you're chasing?
As for the production parts question, I'm not sure how to answer that. Because I suspect you and I have different definitions of production parts. At the end of the day I'm working on Printy for the love of the game. I just want to make a product people love using and is useful. (Hence leading with entirely unlogged-in experience first.)