nothing to do with agents, BOT KYC/AML clampdown due to Chinese organised crime groups operating on the border and the fact that new legislation was passed making the financial institutions responsible for criminal losses.
Easy to answer. The cost of Thai health insurance varies depending on your personal medical history. What tax, if any, you pay depends entirely on your personal financial circumstances.
There are no insurance requirements for the Non-O. For the insurance for the Non-OA you need to select one of the Thai qualifying insurance companies from the list on the website.