I don't think it's too out of line to have a newly formed business to possibly take advantage of what the DTV is offering and you are looking for some work. Do you have any previous experience or work history in this field?
Anonymous participant Use the address of where the business is located overseas, like any standard letterhead from a business that has the business name address and contact info as a header. Try not to overthink this.
Dont mention your Thai address unless they ask where in Thailand you are staying such as a rental contract in Thailand. Stating remote work in Thailand should be simple enough. In the application the embassy will likely ask your current location and or proof of this, so you show the visa/entry stamp of the country you are applying from and maybe your hotel booking.