Typically with a valid IDP and foreign license you can obtain the Thai equivalent license(s) by only doing the physical tests: stopping reaction test and traffic light color recognition test. Practical driving test and written theory test are waived.
Since it's a fixed deposit account Krungsri will withhold tax at 15% of interest earned. Can file a Thai Income Tax Return to be refunded if you qualify for a refund.
Assuming you arrived in Thailand viss-exempt for 30 days or on a Tourist Visa for 60 days you can apply for a non-o visa for 90 days from an immigration office in Thailand. That can subsequently be extended for 12 months.
don't burn bridges you don't have to. My US bank accounts cost me nothing to maintain. Some things are very convenient to do with US accounts. Difficult to open an account in the US when you no longer reside there. No one can see the future, plans change.
I don't think you are trying very hard to understand the useful distinction between a visa and an extension of stay. So, the best we can do is agree to disagree. Best wishes for your future travels and immigration adventures.
a visa (paper obtained from a Thai embassy or consulate pasted into a full page of your passport) is not the same thing as an extension of stay (half-page stamp indicating your permission of stay due to receiving an extension of stay issued by an immigration office inside Thailand). Extensions of stay are transferred from old to new passports. Visas are not.