and this is why you should take AI and throw it in the bin. Complete nonsense from start to finish. Research the old fashioned way, actually do some reading on the subject.
you are only taxed on remittances once tax resident and not all remittances are taxable. If you are living off savings you have nothing to worry about from the tax perspective.
a common misunderstanding of the IDP. It is valid until the end of its validity period, in this case 3 years. There is nothing in Thai law or under the treaty that limits people to 90 days.
nope say nothing, check in with the passport you booked the flight with then when you go through immigration after landing use your other passport. No issues.