Seems that you're making things more complicated than they need to be. Been here 3.5 years previously three years of Non-O retirement visas, but right now on a 30 day tourist changing to 90 day resident, then one year marriage visa (since I do my own visa app's,), and, yes, this is the first year they actually required the TM30. Use T-Mobile from US since I go to the US (as well as other countries where T-Mobile works fine) frequently and can receive calls from the US, plus free texts and 2G data here (on dtac,) and have a Thai number from True (package deal for about THB854 per month includes TV, 100 Mb internet plus Wifi spots and 1 Gb 4G data plus texts, calls are separate but cheap, on a dual SIM unlocked Samsung Galaxy phone. Use my US Citibank account here as their ATM's are free, and offer the best exchange (WSJ +$1MM Forex rates,) and a Thai bank for the THB40k per month transfered by wire. from the US. Line and Skype for international calls from my mobile.