Not true. Even for renewals, a new certificate of residency is required. A new certificate of residency is sometimes required at certain offices even when it's not needed at others, for specific tasks or requests.
Now there's the additional burden of having to get a doctor's certificate even for 5 year to 5 year license renewals, which was not the case prior to Covid.
Pop-up clinics have been established next to DLT offices for this purpose. I don't see the point...as long as you pass an eyesight test and don't have any illnesses that could affect your driving, then a medical shouldn't be necessary for those aged under around 70.
It's quite clear you are. Break the law as a farang and experience the consequences for yourself. You're not Thai...as a farang you don't have the same sort of rights.
I doubt something so minor could be a reason for blacklisting you.
The only thing I'd advise is to avoid that shop, the area near the shop and if you're particularly concerned, the town or city where you rented the bike from.
Same in Taipei. Already people are being asked to have their account balances updated on the day they apply. When I applied, having a balance or statement from 1 week ago was fine (although I think I brought along an updated balance from either the previous day or 2 days prior) but this was not requested.
Savannakhet is developing a pretty bad reputation these days. It used to be the "go to" place, especially for multiple entry marriage visas, but in the space of a few months, they went from not requiring financials (the status quo that had been in effect for many years), to requiring financials but deposited recently being OK, to requiring them to be deposited in a Thai account for 2 months prior to application. This all happened between late October 2023 and early 2024.
They're proving to be tough as nails for the DTV as well, requesting lengthy periods of funds being banked, notarized documents and a whole list of other things.