When they finish processing your application. What does the embassy website say?
You haven't given ANY information for anyone to even begin answering your question. The bare minimum information is your passport country and which embassy you applied at.
But even with that information, it takes as long as it takes.
If I planned to stay in Chiang Mai for 5 years, I would try to find a short term rental so I could move south for the 4 months where the air is unbreathable.
I only know of one province that requires you to be on a long-term visa to get a residence certificate. That's not the case in pretty much every province. So it's not an impediment to getting a drivers license.
The "under consideration stamp" is like an advance on your 1-year extension. When you go back on January 8th you'll receive the remaining year in your passport through December 9th 2026.
The 2nd thing they gave you is a TM47 receipt, which is your first 90-day notification reminder. You need to do your first 90-day report in February.
the agent doesn't open the bank account. They facilitate you being able to do so. They have arrangements with the staff/management at a specific bank branch and they go with you and ensure that everything is taken care of. The bank account is yours, in your name, with your passport and KYC information.
Banks have been telling people these excuses when they don't want to do all the paperwork to open an account for a foreigner for much longer than 2 weeks.
Each bank branch manager sets the requirements for that bank branch. If the one you went to will not do it, go to another one, and another, and another one, until you find one that will.