What are the financial requirements for obtaining an O or O-A visa in Thailand for U.S. expats over 50?

Hello. I'm looking for some clarification and advice. My spouse and I are from USA and both over 50.

We are looking to get the LTR next year, once my spouse can show a little extra passive income on our taxes from renting out our house.

In the interim, we would like to enter Thailand on either an O or O-A visa. The problem appears to be that we thought we only needed to show the 800,000 Baht in our bank on the day of application, but now we noticed we need three months of statements.

We have access to the funds, but with the misunderstanding, we did not yet put them in an account(s) and we want to travel soon.

We also have the option of showing $2,500 in income with those statements. We have a joint checking where my spouse can easily demonstrate that income, but I am a little short.

Based on that, it appears my spouse should have no problem with either the O Or the O-A immediately, but I might have issues.

Based on the above we have a few questions:

1) Do I need to show the money in my account for all three months? I would qualify if I only needed it on application submission.

2) Would they take our total monthly income in our joint account and split it between us? If so, then I would have enough income for all three months.

3) I know I can't open a Thai account without a 90 day visa. Of course, I could go on an exemption or vacation visa. I could then return to the USA after three months and apply for an O or O-A, but that's not very ideal. Is there another option that would allow me enter Thailand sooner and not have to return to the USA to reapply?

Thank you in advance for taking the time to read this, and for helpful clarification or advice.