Burmese workers here are the Thai exquivalent of Mexican/Central American illegals there. Thailand tries to control the border and does deport them regularly, but wages are a lot higher here than Myanmar and there's a never ending and unstoppable flow of them coming in to do manual labor.
That area is not one that has any history of Muslim-separatist terrorism that I'm aware of. It was most likely a straight criminal act. A drug deal gone bad is a definite possibility.
About that very high number of Brits dying here - most are probably suicides of guys that gave all their current and future earnings to their little "tilacs" (darlings) who ran off with them with their Thai boyfriend back upcountry.
Thanks for the info.