you can extend your stay for another 6 months, only have to pay 1900 baht at the local immigration office, without leaving Thailand.
After 12 months is up, you can go out of Thailand and come back again and the clock reset, you can have a six-month entry stamp again. There’s no limitation on how many times you can do this in a single year so in another word, you can stay in Thailand the whole year if you want.
So it is pretty much like multi entry tourist visa, except for longer validity and entry time
I do not think that you would be qualified for DTV, Don’t attempt otherwise you make the it harder for anyone else applied after you. Don’t waste your $400. Soft power is the option. However, you also have to pay for the cooking courses or medical treatment, everything has to be legitimate
Why not just stick with the good old retirement visa ? You have the fund for that. (~22K USD in the Thai bank account, you have 70k) come to Thailand with your visa exemption, and convert to retirement visa while in Thailand. I know one agent in Pattaya who can open the bank bank account ( and buff up your saving for 15 mins to meet the requirements, even it is not encouraged) .