there are some P2 recipes for barbeque sauce out there, but you can't have anything commercial. it's going to have both fat and sugar in it. even in P3, almost all of them have added sugar. if it's just a little bit, you could try it carefully in P3.
yes. this diet is much too low in fiber, imo, so i recommend people take fiber supplements during the diet. also eat lots of green leafy veggies, even if it's an "extra" food- it will not affect your weight loss. i frequently buy packs of "hearts of romaine" and chomp on one in the evening.