Obviously you haven’t read the requirements for the DTV have you it’s know it alls like you are the reason I left the states 15 years ago tell him it’s ok to leave and get denied
You’ll need pretty much worthless Thai insurance for every minute your here even for the 3rd year you’ll always need it plus financials in Thailand for the third year
You’ll need bank accounts here and you’ll need a non-o to get it , that’ll cover him now your daughter will need an ED visa and not sure what you’ll do as there aren’t many places that issue a trailing spouse visa any more good luck