no you have to have an account already and the OP has lived in Thailand for 5 years on an OA visa ,he’s probably wanted to switch to Non-o so left came back on a TV or exempt stamp you can certainly apply for a non-o with seasoned funds in a Thai bank in his name
Depends on your history if you have time on your 90 day just get a re entry permit but if your trying to extend your stay in Thailand they’ll want to know why you didn’t get a yearly extension it’s up to the IO
The non-o based on retirement and extend for a year is the way to go if you want to stay a year without any drama you won’t get two 30 day extensions on two exempt entries in the same year
Did you and your school cancel your ED extension?did you take the paperwork from the school to immigration?If not it could still be active and there not issuing a new visa if anything is active