I'm in the same boat as you. My Thai wife decided I didn't need a motorcycle licence when I renewed my car licence. I only rent bikes when I'm on an island holiday so now I'm not fully covered 😡
Just go and try different branches. It may be easier being away from tourist areas. The main stumbling block is proving where you live. Some banks will accept a sponsor so try your wife's bank first plus other banks will open an account if you buy their expensive insurance. Current money laundering laws have made it much harder to open a bank account. Good luck
there is no specific requirement but your re-entry is at the discretion of the IO so best not to just turnaround, unless you are with a visa agent group.
8 years ago it was 15 days by land entry. You still see this on some websites just like you still see only 2 entries per calendar year. This all confuses ppl just like calling visa-exempt entry visa-on-arrival