Do you have a house or apartment in the US that you'll still have. Or a family member that lives in the US? The best VPN is getting a router that hosts a VPN server setup at your/their house and you connect to that. That way it looks like you're at their house and you'll never have to worry about being detected as a VPN from streaming services.
Correct, there are only 2 financial proofs you can use for the FIRST 1-year extension.
1) embassy certified proof of monthly income
2) proof of 800,000 baht in your Thai bank account
In order to use #2, the money must be in your account for 2 full months already at the time you apply for the extension.
For full details, you need to go to your immigration office, and ask them for their handout for a retirement extension. That will have the specific requirements for your immigration office as they vary from office to office.
It doesn't hurt to ask if you can use monthly transfers, but I've yet to see someone able to do that.
the only thing they will accept if they ask for proof of funds is cash. They will not accept bank statement, bank apps, credit cards or debit cards. Also know that for the major airports there is no ATM machine between the plane and the immigration checkpoint.