Thanks everyone for your responses. Sorry about multiple subjects in single paragraph. Breaking it down:
Primary question I have is how difficult is a spouse visa to get compared to a retirement visa? I'm working with Bangkok IO. My agent (also in Bangkok) tells me spouse visa is much more difficult, requires many forms of proof that we live together at her family home address, neighbors have to sign forms, etc. And actually we are not staying there now, we travel, adding to the difficulty. Is it really that hard?
I understand that IO might not renew my retirement visa as a spouse visa, it might be easier to leave, return on exempt, and then apply for the spouse visa.
Secondary question is how much in advance of visa renewal does the 800k (retirement visa) or 400k (spouse visa) need to be in my bank account? I've heard 60 days, but I'm not sure. For now I'm just leaving that 800k there, in anticipation of the 90 day renewal (to one year).
Comment on leaving 800k (or 400k) in Thai bank account that pays no interest. With current inflation ~5% the real value of this money drops ~5% per year. Even a bit of interest would take the edge off that. Also, if not locked up in Thai bank account it could be invested in something paying more interest than inflation. So that's why I'm interested in not leaving any more than necessary any longer than necessary in Thai non-interest account.