I doubt that you get a new DTV after your 5 years are over. By the way, I live in Thailand for 8 years on a O retirement visa and dealing with the immigration was never a problem. Took me 40 minutes most time to renew it.
Let me guess: Only a fraction of those who apply for a DTV have a reasonable income and want to work as nomads in Thailand. The rest are young people who see the DTV more as a visa to live in a cheap country for as long as possible.
And those who are financially well off will probably not live in a condo in Bangkok.
Believe me, the license plate stays normally on the car for ever, no matter what province you live in. But if you wish to have a license plate from the province you live in, of course you can apply for a new one at your DLT. Takes approx. 2 weeks and of course it has a price.
Correct but once the old passport is punched through it is invalid. Why not transfer all visas to the new one before?, It's so easy, it took me just 5 minutes at the immigration.