Yes, when you enter Thailand on the non-O visa, you need to open an account in Thailand and deposit 800,000 baht in the first week. You then wait 2 months and apply for a 12 month extension of stay.
Yes, online at the Thai Embassy in Aus. It's a bit confusing as it's a 90 day visa based on retirement and the wording is a bit strange. It looks like this...
Yes you need 800,000 baht in a thai account for 2 months before you can extend your stay for 12 months (it's not a visa, you used the visa to enter Thailand).
You seem to be confusing 2 different visas. 1. Non-OA requires health insurance but not 800,000 baht in a Thai bank. 2. Non-O requires 800,000 in a Thai bank to extend your stay for 12 months, but there's no medical insurance requirement.
I used bank statements i printed from the app in Hua Hin and month or so ago (as well as the letters from Bkk Bank), so it seems to depend which office you use.
Someone reported they paid 90,000 baht a few days ago! Sounds like this guy wants them to do everything for him, so i doubt it will be 20,000, probably 40,000+. When it costs about 2,000 to do it easily yourself.