try a different true/ais. You might have to wait for a 1-year extension.
Here is what I did. I first went on Lazda got a 1 year pre-plan (usually a really good deal)
the following year I asked true to convert it to a post-pay and supplied them with my non o. I want to say I didn't need a work permit but I cannot remember.
Highly unlikely on a tourist visa. You need to buy a condo in full for the bank to give you an account on a tourist visa. The best way is through an agent now
SCB doesn't know what they want. Was able to open an account last months on non o. All it takes is going to each branch and trying. I tried one in Nonthaburi and got it. Trying one near central world in BKK if youre near.
the bangkok bank right outside the Phloen Chit stop should give no issues also kasikorn in the building next to will both give non o marriage visa holders bank accounts. Bring your spouse.
You can only open an account on non o visa. After that if you visit a branch near downtown Bangkok especially the central world area its usually easy. Kasikorn and Bangkok Bank are probably the easiest to open with.