You are incorrect. If you have a Thai wife you should get a non o Visa. The non o Visa I have is a multiple entry I can come and go every single day or even three four times a day and they grant me entry for up to 90 days every time I enter. I got my Non o Visa at the Thai consulate in Savannahkat Lao.
With all your documents in order it normally takes 24 hours or less to get this Visa. I have been on this Visa for well over a decade with no issues of me coming and going.
It is 400,000 in the bank or 40,000 a month. But each province interprets that a little differently where the money comes from how long it has to be there
Exact law is you need to change it into your name within 30 days. They're now even starting to fine you if it's over 30 days.
The person who's trying to sell you the bike with only a copy of the book, has a pawned bike. Someone at some point traded the bike for a cash loan and couldn't pay it back. So you're in the position where the original owner, or the finance company that has the book for that bike, will be looking for it, and at some point maybe take it back. Is it worth the risk not having proper title to the bike and possibly losing your investment? Only you can answer that