@Steve *********
and remember, there are restricted areas in which a foreigner may open a business-- what u describe for the food business
"Needs to be high food traffic, quick and easy to produce, tasty. And priced right."
that's exactly what's done by the multitude of thai food carts, all over key "food traffic areas" , all across bkk, Chiang mai, and everywhere in Thailand, all selling every variation of thai food one can imagine-- they produce it quick and easy, it's tasty ( or they wont have repeat customers) and priced very well, so thai rather buy their food than make it themselves.
as for expats, tourists, plenty of KFC, mac's, Burger King, pizza, and now bkk has taco bell.