Your mom and I are so proud of you!!! You did it!!! But on a serious note. Immigration has been awesome lately. I did my marriage visa. I was in and out in like 15 mins. The visit was same day. Super fast and everyone friendly.
Interesting how people make their plans but don't research really the 1 big part of moving here. Unless you get the LTR visa, which is very expensive, you realistically can't work here. There are ways around it... but ya.
Try to get info from a visa center or something to show you will get a retirement visa. If they ask and you show some form of that's your plan I don't think they will pry to much
giving up US citizenship and from what it sounds like. Applying for thai citizenship. Is a bad idea. The US basically owns you. The cost alone is absurd. Especially if you are working adult or plan on getting any sort of retirement