Probably a wise move. It seems you're struggling to meet the criteria in Thailand. I did it the easy way by getting almost two years from the OA and during that time I started the 65k monthly transfers. That's a few years back, but like yourself, I'm on a Public Service pension, so meeting the monthly amounts is no problem. I didn't want to touch my Super lump sum, as once you withdraw from it, you can't put it back, so you lose the benefit of the tax-free umbrella.
Check the embassy rules where you apply for the visa. For example, many embassies require 3-month insurance for some non-O visas (For example, Australia requires insurance for 90 day non-O retirement visas). Universally, both OA and OX require insurance.
I don't know what "the other scheme" is. All I know is you need 12 x 65k transfers (one year's worth) OR 800k deposit for three months prior. I think that's where you're getting confused
And that is exactly the reason so many people find it difficult. If you read my earlier comment you will see that I proposed people should take the OA initially, they then have two years to get the monthly transfers happening. I've no idea where you get this three month story from.
You should be asking the embassy or consulate where you will apply, it's their call. I'd say for a single entry you might be ok, but it would be your last for a while
You can't remain in Thailand for a year on a tourist visa. Get an ED visa and learn the language or Muay Thai. If you want to stay long-term, get a long-term visa. Simple enough