You will be rejected if you try and use funds in a business account for the 500k baht requirement. Use your business account to prove your work, matching up invoices to receipts for example
There's really only 2 visa options that allow you to legally work remotely for a non Thai company outside of Thailand. The DTV is the easiest one to get, the LTR Remote Worker one has very high requirements for both the applicant and the company they work for