I opened an account with SCB recently, I had no problems with just my badly damaged passport that had just been through a standard cycle in a washing machine. It is extremely hit and miss which bank and if they feel like it. Just try one at a time be polite and smile a lot.
I agree with you on the paperwork, I just updated my passport details with Bangkok Bank and had to sign 18 documents and photocopies, the same task in SCB was completed with one document.
I have had a Bangkok Bank account for many years and wanted a 2nd account, one for immigration purposes and one for everyday spending, despite being a customer for many years they refused me. I walked into a Siam Commercial Bank in my local Lotus’s and opened a new account within about 30 mins, no problems and I have a very damaged passport. It is very much luck of the drawer and patience is needed.