Thanks so much for your kind words. I'll try to get to the parts of your post that I am able to answer, I don't have my thumb on the pulse of American Muay Thai so I have no idea how to speculate there.
Covid has had a big impact on Muay Thai in Thailand. It has shut down a lot of the provincial fighting, which was the true lifeblood of Muay Thai, put innumerable people out of work, shut down gyms and had many fighters quit for lack of income, created a different structure for fights so that the 3 round "entertainment Muay Thai" has become more prominent and traditional 5 round fights are only being put on by the Old Guard Bangkok promoters. The future of Muay Thai, in my eyes, looks grim. But for folks who like the "international" entertainment style, the future looks bright. It has not affected foreign fighters in a negative way; if anything, the opportunities have increased to fight on bigger shows (money/exposure wise) because they're these 3 round promotions that want every fight to be Thai vs Non-Thai.
Likelihood that you can support yourself financially off of fighting alone is vanishingly small. Working online and teaching English seem to be the most frequent income bases for long-term stay in Thailand.
For Muay Khao training I'd recommend training with Kru Diesel at his gym in Singburi, https://www.fighthousethailand.com/sing-buri