useless trivia: What Word Means: A Conman'S Assistant?

Questions

Chain with a hat as a logo, makes roast beef burgers among other things.?

Big Mexican food chain, ring ding a ling, making you run for the border!?

Out of the two big cola brands, which one do they sell?

Soft Bun, Pickles, Sauce, Pattie.?

All of their products seem to be prefaced with which 2 letters?