If I were you, I’d go to savannakhet, procure a single entry non O visa and go to the bank with that. Then, you can apply for an extension of stay after depositing relevant funds. I would go out of my way to avoid paying anyone and playing their game, but I’m just a stubborn c*nt 😆
I can’t comment on the process for American citizens, but I went to my embassy in Bangkok to affirm I wasn’t already married and get a certified copy of passport. I then had to get these translated and authenticated before applying to register marriage in Thailand. Cost approximately $150 for everything.
I’m unsure what you mean. If you’re applying for non-o based on marriage to Thai national, you’ll need to show either Thai marriage certificate or authenticated and translated copies of foreign marriage certificate.