hmmm you won't be loaded but it's ok if you're not an habitual bar guy or massively into golf. If you're into bar girls, you've probably got about 18 months!
No anxiety for me, I've seen the tax bands, I've seen the allowances so have a rough idea of what it would mean for me and can afford it with no issues. Always good to be prepared and if it doesn't happen, I think there's a less than 1% chance they will drop it as it's aimed at rich thais rather than expats, then thats a bonus. But I'm set for it to happen, anyone not taking that approach will just have to deal with the fallout if/when it does.
If you can't prove you've paid the tax, as you've rightly pointed out, do you think the thai tax office will say never mind just let us know when you can? If they tie it to extension approval which is my GUESS they will, then you won't get the extension if you haven't got a tax receipt. I can't see any other way they can do it. It's already stipulated on the marriage visa form, No 6 I believe.