Hey Mtlbiker this is so cool, you've gotten this far by yourself, congratulations! I think it can even be nicer to just have it as a hobby on the side - no pressure on selling them, just doing it for the passion of creating.
The thing is, I would need the arm to sew parts I can only reach if I can put the bag on the arm. But thanks I'm considering getting a flatbed so it can work as a flatbed machine as well. I'm still trying to figure out which is the best choice - I've just found an old Pfaff 335 H3 model on marketplace, are you familiar with that model? It is way cheaper than every other option at the moment.
Have a nice evening!
Blanka