You can take as much as you want, but generally if it's over $10,000 you need to declare it at the airport. It's not a problem. This rule will be slightly different for each country, but this is a fairly common rule. It's to stop money laundering. When you transfer money through the bank this is done automatically.
I need to get a criminal record check to present to my next school, which is not in Thailand. This is pretty standard when leaving any country. I have them from four counties already.
my case is a bit complicated and i did use an embassy letter when the first covid visas were issues. I dont believe that was the case in January and we haven't needed one since.
My work permit ended in January. I went to immigration got the visa cancelled, got a covid visa. I'm still here and could apply for another covid visa until mid September. But we're done, so going home instead.