the visa is in your name not your company, so personal up-to-date bank statements needed. Ask AI to write employment letter giving them what they want, addressed to Thai Embassy, job requires remote working, and sign it as a Company Director and headed paper.
I don't know anything about Spouse visas but when I applied for my DTV I had to upload the most recent bank statement I had showing I had the required proof of funds so I imagine you would need to top up the account before applying for the DTV. That was through London Thai Embassy. As the other BM said all embassies have differences.
I used tax credit certificate from Revenue Commissioners (HMRC in d UK). You could use bank statement or Council Tax letter as proof of address I reckon.
I initially sent copy of contract, which I got AI to do 555. They then came back looking for an employment letter signed by a Director or HR person, addressed to the Embassy, saying what my job was, length of service, and That I was required to work remotely. That letter + up to date bank statement was additional info they came back looking for. Once I uploaded those I got the DTV the next day.
I got a DTV from London Embassy. I am an employee of a company in Ireland and get paid monthly by them. I showed the 500k proof in one bank account that doesn't show my monthly wages. So I reckon you'll be fine. Have an up-to-date bank statement, not one a few months old. Employment letter needs to say Required to Work Remotely and be addressed to Thai Embassy.
Time expired from when you started to when you submitted documents? I think the window isnt very long, maybe 2 weeks from when you start the application to when you're supposed to have all your documents submitted. Start a new application tomorrow.