What crackdown on existing visa requirements? There isn't one. The only crackdown is on people abusing visa exempt entries. Those people have no visa at all.
First of all, you won't be getting the spousal visa in Thailand, because the non-O IS the marriage visa. It's literally called a non-O VISA. In Thailand you will be applying for extensions, not visas.
Second, you are mixing up marriage and retirement. Retirement extensions require money to always be in the bank, but marriage does not.
The requirement for a marriage extension is 400,000 baht in your Thai bank account for 2 full months already at the time you apply for the extension. Once you receive your extension (after the under consideration period and possible home visit), you can then use the money for whatever you want. You just need to have the account back at 400k another 2 months before you submit your application for your next extension.
You need to check with your immigration office when you arrive in Thailand to see if they accept the monthly transfers as proof of income. There are some immigration offices that will only accept "monthly income" if it's the paycheck from your work permit job in Thailand. So if your office is one of these offices, they will not accept your monthly transfers.
To be honest, it doesn't matter. Just put something in there. A re-entry permit is valid until the end of your extension regardless, and they're not going to ask you for your trip information to verify anything. You can put whichever trip you'd like.
Although given the current situation, might be better if you just put the Belgium trip.
I have heard that people arriving for Cambodia no longer qualify for fast track, either the normal one or the "safe entry" one. But I haven't heard anything about a special line. Perhaps the people arriving on those flights are now allowed into the terminal like normal and are instead ushered to a special line that way? Would be interesting to hear if anyone has more information.
someone in a news article yes. And the unmentioned details is they have spent a lot of time in Thailand this year and were rude to the immigration officer and wouldn't even get off their phone.
But many people are denied entry using this every day that you don't hear about.
If they ask you this question, it's because they already want to deny you entry.
But with the crackdown currently going on, it's likely going to get asked to more people than previously.
Who has and has not been asked literally makes no difference for you. If you are asked, you must have it or you will be denied entry. It's as simple as that. Even if 1 million people before you were not asked, you must legally have proof of funds to enter Thailand as a tourist.