Each immigration office sets their own requirement.
If you cannot get the certificate of residence from Nonthaburi, you can get it from elsewhere. I got my license in Chiang Mai, where they only require a TM30 and 500 baht to get the CoR the next day. You can use a certificate of residence from anywhere in Thailand for a license renewal, though that's the address that will be on the license.
You can also try contacting FatBoys, as they help a lot of people with licenses in Bangkok, and you're practically in Bangkok
If you're going to get the initial 90 day non-O visa in Thailand, then you need to apply for it in the same place you will be applying for the first 1-year extension. No immigration office in Thailand will let you apply for the 1-year extension based off a 90-day non-O visa that was granted by a different immigration office.
If you gave me the choice of sitting around on my phone, or spending an hour doing paperwork, I would choose sitting around on my phone. But I might consider the paperwork if I'm going to get commission.
laws only matter if there's enforcement and if the penalties outweigh the benefits.
Unfortunately Thailand is lacking in enforcement and especially lacking in meaningful penalties. Most of the time the fine if caught is less than the benefit of a single successful instance of breaking that law. And since the odds of getting caught are far less than 100%, it always makes sense to break the law according to game theory.
It's not a Kasikorn bank requirement. But it might be a requirement for the branch you went to in order to make all the paperwork required for them to do worth it.
Do you have a non-immigrant visa? A certificate of residence from immigration? What happens if you tell them you want the bank account without the insurance?
You can try other branches or other banks.
Worst case scenario is you bite the bullet and purchase the insurance. You might even be able to cancel it shortly after for a refund.
most agencies now will only assist opening a bank account if you're also converting or extending a non-immigrant visa with that agency. I don't know of any agencies that can do bank accounts for tourists anymore.
You can only get a DTV from a Thai embassy or consulate. Obviously there are none of those in Thailand.
You must physically be in the jurisdiction of an embassy to apply there, and must remain until the application is processed. This takes anywhere from 3 days to 1.5 months depending on the embassy.