they lied to you. I just opened with Kasikorn two days ago on a 90-day non-o. Zero issues because I was on the non-o. I’m not eligible to apply for my extension yet because my funds are days old and need to season for 60 days. You do not need a one-year visa to open an account by law. That’s just Bangkok Bank paying penance for previous misdeeds.
they’re misspeaking. Most non-o visas are for 90 days, after which you apply for a year-long extension of stay, which people confusingly refer to as a “longterm visa”. Any non-tourist visa that you qualify for will allow you to open a bank account. There is no catch-22 that people keep bringing up. Leave the country, apply for and receive a non-o. Ask whichever bank you want to open with what their requirements are, return with those requirements, and you will have a bank account in your name. It can be tedious, but people do it all the time without issue.
I haven’t even been in 30 days on my non o based on marriage and I’m already considering switching to a DTV, it’s insane. You read about it, but going through it is another matter. Pure insanity.
I did not. I have a Texas driver license, changed my physical address to Seattle because I have friends in Seattle, which gives me the option for local pick up if I need it.
But if you did want to get a license from another state, South Dakota has a special program just for ex-pats/nomads where you can arrive in South Dakota, arrange with a local mail forwarding service to get a physical address, then use that address to get your South Dakota drivers license and state residency. 
Just grab an address from any of the mail forwarding services, tell them that’s your new address, done. I chose one in Seattle. Gave it to the USPS for my mail forwarding address, changed all my bank addresses, VA and military pension addresses, no issues.