If you've had 65k a month for the last 12 consecutive months you shouldn't need an income affidavit. All you need is a statement from you bank (you have to order it, takes 2-5 days). Which immigration office did you go to? Its possible they misunderstood you, or didnt care to ask the details.
The initial Non-O needs to be 800k. Your 2nd yearly extension (and then on) as long as you deposit 65k a month into a thai bank account you can switch to the monthly income method, but that's because you'll have 12 months of 65k into a thai bank.
Not sure why youd ask on the Wise fb group, has nothing to do with visas.
For a retirement visa with the monthly 65k deposit, you can either do that with 65k a month going into a thai bank account, or an income affidavit from your embassy, and most embassies don't issue them anymore. That means, and wait for it, you can't use to monthly 65k for your retirement visa. You'll need to put 800k in a bank account.
You can't, you can only get a 5 year license if you're on a non immigrant visa. And you can only get an IDP on a 5 year license. It's the same for thais and foreigners, there's no work around.
The cash requirement was never removed and has been around since the 90s/early 2000s (it used to be 10k). In reality, it's the most commonly used criteria to deny entry.