Thai government got loaned way too much by the banks, I dont think the baht will do what you are predicting. I think we are heading to 35 within a month or two.
Oh, I understand why you asked my visa. You can open Bank account with Bangkok Bank regardless of the visa that you have, but the certificate of residency is non-negotiable. You can't open an account on your own without it unless an agent bribe manager, or manager bribe you.
I am currently getting the marriage extension, so yes, long-term visa. The bank manager is operating fraudulently. Most likely he is used to work with agent so he is by-passing that with you to ask you for a bribe. It's a pretty big bribe because with an agent it will cost you around 5k baht to open a bank account without meeting the requirements. You cannot open a bank account in Bangkok Bank without the certificate of residency (unless with agent or other form of bribe). The certificate of residence is easy to get at immigration, I got it last week. You need to go there and fill a TM30, then ask for residence. You just need the blue book and copy of ID of whoever you are renting from.
I live in Thailand for 10 years and I have no idea what you are referring to. You do not need a visa to enter Thailand unless you are required "visa on arrival" (selective number of countries).