yes seen copy of Thai ID signed is sufficient instead of Tax number if it's an individual Thai person.
Correct me if wrong but listing documents and merging all the pdf's onto one file solves the problem of presenting documents in the first application. Just trying to get it correct first time so I'm planning ahead of application.
asking & receiving in Thailand don't always follow each other. I have asked, I use my condo in Malaysia where I spend a lot of time so applying there makes most sense..