Now my friend, with all due respect but that is gobbledigook. How many years do retirement visa exist? How many times did the rule change so much that retired people have to leaf the country. Yes, the amount you need to stay has increased, you have to report every 90 days and then you have the hassle with the TM30. But the changes are very minimal.
Visa changes are mostly for Tourist Visa or better the Entry without a visa. Somethimes it's 2 times a year, then only restricted on land borders but not airports and so on. There, the changes happen. But not with the retirement visas. So stop to worry. Think in solutions to your problems and don't create problems that do not really exist.
If you do not trust the Thai Banks with your 880k Baht, then use an agent. You told us your retirement income, you are getting enough to pay for that with ease.
Move to Hua Hin or better Pranburi. Very nice place at the sea with good air (well as good as air can get in Thailand). Hundred of houses to rent, so you should have no problem to find a nice one. Fantastic natur, great beaches, good food, modern Hospitals and it does not stink at every corner of marihuana. Save from earthquakes too.