let's say your multi entry visa expires tonight at midnight. You could go in and out of Thailand every hour until midnight and be stamped in for a year each time. Of course it would end up being the same date a year in the future. So if you want to go out after midnight, your visa has now expired and you're on a permission to stay stamp, you'll need to buy a re-entry permit before you leave to keep that 1 year permission alive, otherwise without it the moment you stamp out you end your 1 year stay permission.
no, not before the visa expires its multi entry, before the extension expires, your visa let's say is already expired. Say your visa expires this May 1st, on April 30th you re-enter/return to Thailand and get stamped in till April 30th 2023. The next day your visa expires, so now if you want to exit and return to Thailand any time before April 30 2023 you'd need a re-entry permit to keep your April 2023 stamp alive. You'll need to buy a reentry permit every time you renew your yearly extension or just before you leave Thailand.
Ask a final note, after your last entry before the visa expires, you would need to get a reentry permit to keep that 1 year permission stamp alive. When your year is up if you get another extension you will need to buy a rentry permit again if you plan on leaving. You can buy a multiple or single entry permit.
800k minimum balance is 2 months before and 3 months after initial 1 yr extension. No health insurance requirements or criminal record checks for Non Imm O, that is for OA.
you'll only be stamped on till Jun 2nd. If you haven't already applied for a 30 day extension you can buy one when you return to allow you to stay until July 1st or so.
not really possible to know how immigration will deal with extensions for this visa in September. We don’t even know if the program will be extended. Right now at a minimum it’s a viable option for around a six month stay whether you’re currently in the country or planning to buy one in your home country and travel here.