They couldn't wouln't scrap visa already issued. But it is within reason to assume that they might "tighten" the issuance of new DTV visa in the future. Getting a 5 (almost 6 year) visa for a days cooking class or a mere doctors appointment might be something they could rethink in the future.
Regarding financial proof modalities, you should double check with the consulate where you want to apply. They all cook their own soup. As for a certified translation into English - see the link I shared above.
Just to be clear ... the DTV visa for spouses is for spouses of DTV holders. Just mentioning this, because quite some people confused this category and thought they would qualify for a DTV based off of being married to a Thai. Having said that, I used the following service once, as it worked remotely and was cheap:
I will share my report once I got the visa or any requests from Berlin RTE. Submitted a company registration papers of company I own 100% + letter stating me being CEO of said company and free to work remotely from wherever (including Thailand) + latest bank statements of one of my savings accounts.
That is not a question of destination country, but rather a question of your home country. I would always advise to get a reputable insurance in your home country - where you understand the law and know and can enforce your rights if you ever need to.
I have always only submitted redacted bank statements. Redacted almost everything expect my name and the opening and closing amount of the bank statement. Clearly neither bank account number and certainly not the details of individual transactions are their business. Might depend on the laws of the country you are applying in, though.
Thank you for sharing your report. How long was the turnaround time from submission to issuance? I submitted similar documents for Berlin. But they have not even bothered to do the first step (checking of documents), yet.