That's Denmark. Fortunately other countries do not have that stipulation. Best for Danes to come in on tourist visa and to convert to Non-O at an immigration office. There's no retirement requirement there
Not required, as the return would indicate a sequence of '0's. As pension payments from Australia are not taxable in Thailand there's no requirement to show them, as they are not assessable
Apologies. I always look at things from the Australian point of view with the assumption that other countries have a similar DTA, but as Brits and Americans have pointed out they don't have the same protection as Australia. If retirees are only importing pension payments these are not taxable in Thailand, hence a tax return is not required