I don't know as I applied and got visa in my country, though I've read a lot in this group and the consensus seems to be it's near impossible to open an account now on a tourist visa. I've also read that a good agent can open one with you for a few thousand baht. Maybe you can ask on a new post for recommendations for a reliable agent to help you π
You'll be able to have a very comfortable retirement with 64k/ year in Thailand. Brandon will have very Sage advice for your Visa questions. I'd recommend renting vs buying, as it will allow you to live in different areas till you find the city/Province you like, or if you're already set on a City, you can rent different places until you find the residence you're most comfortable in that City. Best wishes π