Step 1: put your German rule book aside. Step 2: decide how would the American do it. Step 3: the American would just hop on a plane with out a visa or return ticket ($14 onwardticket if demanded). Step 4: Stay for 60 day visa exception then fly to the next Oktoberfest in Penang Malaysia or Bali, Indonesia, then come back for more Thai beer
The USA requires the wife to have lived in the USA for 5 years before paying out benefits for a spouse in the husband's account. Under 18 foreign born Children with a us report of birth to the embassy get monthly checks from death of father, no need to ever live in usa
Don't bother with extensions, you want to look like a tourist using Thailand as a home base to see Asia. Best to leave every 60 days and visit Malaysia, Indonesia or Philippines for a few days and then come back. Border runs are a waste of a whole day and waiting in line at immigration will test your patience.