Because of Thai National Day celebrations, expect even the Visa Section at the Thai Consulate to not be processing visas at full capacity.
For instance, this past Monday they held a grand reception in the evening, so expect that the Consulate probably were working more on National Day celebrations
It is at the discretion of the Thai Revenue Officer or Thai Customs Officer if they determine if one who holds a Destination Thailand Visa (DTV) has a domicile in Thailand or not....
Nope, cannot get Supplemental Security Income (SSI) in any foreign country (outside the USA), but getting Retirement Social Security (RSDI) anywhere in the world as an U.S. citizen is no problem