Hi Pauline. I am a coeliac and very much a cross contamination worrier. I have done two cruises s with P&O so have some experience. I can’t answer all your questions but can tell you what I did. I ate in the MDR nearly all the time. Did eat salads etc in the buffet once or twice. I just made a decision not to eat anywhere else to avoid chances of mistakes. Had afternoon tea in the MDR one afternoon that needed to be ordered previous day. One tip about bacon at breakfast. Ask for it to be done fresh in the kitchen with usual precautions obviously because the bacon on self serve is sometimes drained on or near bread!!!!! Also had desserts from the buffet but they were kept in a special cabinet at the back on their own.