The requirements are getting stricter as time goes by, and they recognize the abuses people are doing to scam the system. This is how Thailand operates with anything new like this visa.
As long as you've got the equivalent of bt500,000 in your personal bank account you should be fine. You might be asked for your latest income tax filing though. The embassy in Yangon Myanmar is fast.
that is not accepted at all, and never has been. The only thing accepted for the first year for someone with a UK passport is by having bt800,000 in a Thai bank account in your name only. Nothing else is accepted.
If you are on an actual visa you bought before entering Thailand you go to the Chaeng Wattana immigration office, but if you received a visa exempt 60 day entry then you go to IT Square Mall on the third floor at the Lak Si office. Those are your only options.
legal age for what? Nothing I am aware of has the legal age at 17 in Thailand, and I've dealt with this for over 20 years, living here for 14. 15 is a legal age for some things, 18 for other things, and 20 years old for most other things, but I've never heard of 17 being the legal age cutoff for anything.
well, with the right amount of money in your Thai bank account you can immediately change to a retirement visa extension without leaving the country, but that only applies if you are over 50. The big advantage is being able to legally get a work permit, and a number of other benefits not available at all to retirement visa extension holders. It is a very attractive visa extension for living here long term. As an example you can never apply for permanent residency, or citizenship, on a retirement visa extension. You can on a marriage visa extension. The financial requirement is cut in half also, but for someone thinking their marriage won't last, and is over 50, then yes.
There are no rules in place now so any changes made in the future don't concern you for the five years the visa is valid for. You are grandfathered in to any changes. That's how Thailand operates with something new, like this visa.