I'll be the voice of dissent. The heart and soul of good bbq is simplicity- the art of making delicious food from a few simple ingredients, lower end cuts of meat, time, smoke, and patience. Most people expect bbq to taste like bbq, not fancy French cuisine. I think I'd do the shoulders and ribs traditionally and save the foie gras for some kind of appetizer where it can be itself and can be appreciated for what it is. Hell, here in NC, people would turn their noses up at the bbq if there was a little too much ketchup or sugar in the sauce, much less goose guts.