I've done it for several years here, it's hard work 😂 check out the requirements for a retirement visa. Basically, you need to keep 800,000 baht in a Thai account for most of the year. *you can dip down to 400,000 baht for some of the year. You CAN keep that money in Euros/pounds/dollars in an international account with one if the Thai banks OR you can show the required monthly income (which is a but of a pain) going into a Thai account for a year. As for your younger spouse - unsure if he could attach himself to your visa (as a spouse) for a retirement visa - this would be my question in your situation. And, details of visa requirements are readily available - you don't need an agent - just a LOT of patience and someone who can speak Thai. Some DO use an agent in-country when they are already here and 'work around' having the required capital for a retirement visa. It's 'legal' but a bit of a grey area - can cause complications later if you go down the proper route.
Yes and no. You can get a visa, work permit, and teaching council approval for a limited time - but that's getting harder. You now have to complete and pass the TCT's 7 module program. It's specifically designed to stop people rocking up and teaching without any formal training (TEFL's are something but nowhere near enough) .
Take a few holidays here first - travel around and see where you like. Have some fun. When you hit 50, and meet the financial requirements for a retirement visa, then do that. No need for a full on commitment straight off - be smart, figure it out, then get on a retirement visa at a later stage.
There is a list of visas on the embassy website. You could (depending on your nationality) apply for a tourist visa for up to six months. Take a look around then use a local visa agent jn-country). Or, save a lot of hassle and apply for a retirement visa before entry. (Then convert to a yearly extension to stay).
Sit down and negotiate, it's true (especially post covid) that people are skint. Invite her for a sit down and ask her to do a pre-inspection/indicate what (if any penalties) may be incurred. Be open about your concerns about the sofa and maybe you can come to an agreement rather than leave it to the last moment. Take a Thai friend or translator if her English isn't good enough.