We recently received our LTR-Visa via the E-visa system (within 3-days of applying) offered through the Thai-Embassies, after applying from outside Thailand through the BOI. We did not have to make the journey to Bangkok.
LTR-Visa's are preceded with a visa-endorsement letter from the BOI (issued via an agent if you use one), then you apply for the visa itself. We were outside Thailand when we applied so we used the E-visa method via the Thai-Embassy in Kuala Lumpur. We are renting for one year but if yours is shorter, you will need to test it with the bank. Certificate of Residence is issued by an immigration office, and for ours, they asked for passport, 4 x colour PP photos, rental agreement, copy of visa, complete their form, and pay 1,000THB.
BKK bank and others have tightened up in the past 2 weeks following uncovered fraud in a Pattaya Branch. Those on short term visas may have difficulty presently, therefore may need assistance.
My wife and I (both European) have just opened accounts with Kasikorn in HH using LTR-Visa, LTR-Visa Endorsement Letters, Passports, and Proof of Residence. We had to queue for a while and the process took a good hour or more. We also went to Bangkok Bank out of interest, and they wanted all of the same documents and an ID from our Country of origin - they said they would accept my International Driving Licence as my Country of Origin ID, and waive my Wife's. They also said, anyone renting must show a TM30, not just a rental agreement. Banks have been unnerved by the fraudulent activity uncovered in the passed two weeks in a Pattaya Bank Branch - they are tightening up and anyone with short term visas may need help.
TDAC is a mechanism to capture your name and identity to check out your background, check if you are not blacklisted, check you not on the wanted list etc before attempting to enter the Country.