You can't just "switch" from OA to O. You actually have to leave Thailand, come back in on visa exempt, and then apply for the O at an immigration office. I know for a fact Bangkok Immigration allows the use of 12 x 65k transfers, but each immigration office has their own rules
The 65k/month transfer is in lieu of the 800k, and is the most cost-effective method, as the 65k you can use as soon as it hits your bank account. The 800k is effectively tied up for the rest of your life
Because the "funds for longstay" category must be shown as an international transfer, so Wise will intercept this transfer to ensure it is notated correctly. Mine is usually overnight, but can be up to two days
Super Fund worked for me to get OA visa, and more recently DTV.
Not often proof of pension is required, but I'm guessing that provided you can show the 65k transfer has come from a number of pension funds you should be right. It's usually one of those "depends on the immigration office" things