what do you put in the Thai national id number? It has a red astrix so you have to fill it in, I'm guessing westerners living there don't get a Thai id number.
I'm just going by what Ive read, don't you only have 180 days and have to then leave and come back? Google is confusing about the DTV, could you explain what you need to do for a DTV and what happens when in Thailand in the DTV?