I'm hearing rumors recently about a digital nomad 5-year visa for Bali, Indonesia. But haven't heard anything similar for Thailand, and the Bali visa isn't a done-deal yet.
I would recommend looking into an education visa, if you have any serious interest in learning some of the local language. They will expect you to actually be learning it, and not just paying for the visa. Muay Thai is also an option, I understand. I don't think getting in shape would be a bad thing, to boot!
There is a visa by investment, but from what I recall, it's in the $260k USD range that you'd have to spend in order to get that. The Thai Elite would be a great option, too - if you have $16,500 USD to spend for 5-years. But with that, if you're staying in Bangkok especially, you still have to report every 90 days, but can just drop your passport off at the T.E office and they'll take care of everything for you.
