What are the steps and requirements for applying for an O-A Retirement Long Stay Visa from the US?

Any helpful advice would be most appreciated!

I was planning on applying for my O-A Retirement Long Stay Visa in the states(via mail to Los Angeles) next month on my annual family visit. However I made the error of securing the 800,000 baht 3 months ago in my Thai bank account(this would have been for my extension, of which I cannot now afford, the 800,000 for 5 months and 400,000 baht 6 months of the year), and just noticed today it should be in my US account - of which I no longer have.

Question 1: Has anyone gotten this visa recently in the states, and used the 800,000(or US equivalent)? And if so, was there a minimum time period to have had it in the US bank?

Question 2: Can anyone recommend the least expensive way to get the money there, by money order, certified check, etc. in which I can immediately open a US bank account and deposit it upon my arrival in order to get the letter showing the funds in the US?

Question 3: Has anyone opened a US bank account recently and what/how many forms of identification were needed?

Thank you in advance! 🙏