Do up a Will. You could also leave some cash stored with the Will or with a letter you've left for your loved one's that will tide them over until they can access the bank accounts etc.
I wouldn't stress mate. Even the tax professionals...have no idea and they even have different opinions amongst themselves of how things will play out, so I'd just sit back and wait for the dust to settle. Many of the fear mongers always commenting have probably already obtained TINs or been turned away so I wouldn't listen to 99% of them as everyone's circumstances are not exactly the same. The funds you're bringing in may not even be considered assessable. If you're here for over 6months do you need to lodge a return if your source of funds are from savings prior to 2023? or if you say sent less than ฿100k for the entire year? Or you're living on money you sent to Thailand years ago, Or your funds come from a pension that is only allowed to be taxed by your home country? Or or or or...
No not exactly, the Australian Government asked for my address on my identification to be correct so they could issue my daughter's 1st Australian passport. Nothing about a pension.