I had the identical to you, and easily switched the visa with Immigration to a retirement visa, and cancelling my work permit took one visit to the council offices and cost about 50 baht if I remember correctly.
Elaine Ross the impression I got was that the fact I had a local Thai person with me to "vouch" for me was what made it easy for me. Or maybe just lucky, who knows.
Elaine Ross yes you can, though many/most banks/branches will say no. It is up to the individual branch, I opened with kasikorn whilst on a tourist visa.
My uninformed opinion is that a retirement visa is the easiest route of he has the correct funds...800,000 baht in a Thai bank account under solely his name.
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