Think depends on how long ago. 20 years ago it was not so strict as now. Opened a bank account with no visa. And they where happy when I put in the money. So violating the law ? Think there is no real law for opening a bank account. Bank regulations ? Maybe now but sure not 15 / 20 years ago. Bank account opening rules where, and think they still are, on their web sites for a foreigner....
Well, if it's really only 1 year, then maybe look on the thai website in y'r home country if you can fulfill the requirements of a non imm O-A visa. Then you don't have to worry in Thailand besides every 90 days a notification from the Thai imm. Even possible to do that online. You don't need a Thai bank account. Should you want to stay longer you got a 'free year extension' after doing a border hop just before the visa expires. But....you have to have a health insurance for the whole year or the time you want to stay a bit longer on this extension. It's a bit more difficult to get this visa in y'r homecountry, (like a police clearance and health insurance) but then you are ready to go.
If you want to retire then I think best option is the non imm. O (Without 'A') so you can stay 90 days. After e.g. 60 days you can get a year extension but then you need a Thai bank account, 800k฿ in that bank etc. etc.
So for about 1 year only, I think if you can fulfill the requirements for the NON IMM. O-A visa, it's the most hustle free time in Thailand.
I don't know that restrictions of 50k฿ when transfering from a Thai bank to another Thai bank, or paying something. I think you have a limit within y'r app settings.
I don't know Krungsri, but for Kasikorn and Bangkok bank it's:
Kbank > "more" > set transaction limits
Bangkok bank > settings (upper right corner 'wheel') > Daily limits
Maybe check these settings in y'r app 🤷♂️
Long time ago, but that is with international transfers from y'r 'home bank' to a Thai bank and think not relevant with y'r remark, there where indeed limits set of 50k฿ with most Thai banks. Untill now I still think it is SCB, Kasikorn and Bangkok bank which don't have those limits. But as said, only aware of international transfers, not local.
Just asked a dutch friend. New passport about half year ago via Dutch Embassy in BKK. In that field (In Dutch 'Ministerie van Buitenlandse zaken') So 'Ministry of Foreign Affairs' in English. But if needed a city he uses 'Bangkok'.