More fear-mongering? Already negated. If someone REALLY wants me to complete a tax return and put a '0' in every space, so be it! But it ain't going to happen!
Unfortunately, many retired expats do sincerely believe they are adding substantially to the Thai economy. They think their 65k a month they bring in is saving the Thai economy. With a mindset like that it's difficult to shift this "we're going to be taxed" notion embedded in their brains!
I've been in Thailand for 15 years. Never needed to complete a tax return, and don't have a Tax ID number. Further I have no intention of doing either. If "they" want to audit the 65k I bring in every month, they are free to do it. I've 0.00 to hide!
Very long-winded response, but a couple of things you're wrong about. Pensions are only taxable in the country in which they're received. End of story. Forget about tax credits. Not applicable to pensions. And whatever gives you the idea that ATM withdrawals will not be taxed?