What are the requirements for applying for a Non-O visa and opening a bank account in Thailand?

For the money part you need the 800k in the bank from abroad for the initial application. For the extension it needs to be in the account for 2 months prior and stay for 3 months after. Can’t go below 400k and back up to 800 two months before your next application.

For the verify passport part I have no idea. Perhaps try a different bank branch.

Sadly you are on the merry go round of Thai banking. It's likely that if you go back tomorrow and talk to someone else you will be asked for different identification! I did this in January this year and tried multiple banks in my local town, they All asked for different I.D. We went to a local shopping centre with 5 banks last December (when I was here on holiday) same thing. When I retired here in January we went to our local BAAC, they wanted a work permit for my retirement visa! Tried another 5 or 6 banks in Ubon (they wanted a variety of WP, letter from embassy, retirement visa in passport, marriage certificate etc) . We finally stopped at another BAAC branch where a lovely lady photocopied my passport, no questions asked. Hallelujah, a bank account. There is no rhyme or reason to opening an account sadly. Hit EVERY bank you can, preferably with a Thai speaker, dress smartly and take every bit of paper with you. Eventually one will open an account but you will be non the wiser why. Remember, only Kasikorn, SCB and Bangkok banks can accept international transfers over 50,000 baht..... it took me a while 🥴. Good luck

Personally I would try a different branch of the bank - they all seem to have their own rules. I've never heard of Immigration having to certify your passport before.

Your embassy can do both. Verify passport and address as needed by Bangkok bank.

Other banks are generally not helpful.. some may get lucky.

800k transferred from abroad, no seasoning required, for the Non Imm O visa. 800k seasoned in a Thai bank for 2 months for the 1 year extention of stay.

For the verifying passport part, that is done at your embassy, not at immigration. Your embassy has to verify that your passport is real, and belongs to you.

You just have to keep trying different banks and different times until you find someone to open an account