Read through those threads and you should have all the info. you need. Just remember to mention the allergies when you call to make your priority seatings, call the chefs at the restaurants at least 5 days prior to your trip, mention the allergies again to the CMs at the restaurants when they seat you and be sure to ask to see the chef at each restaurant. The chef will go over the menu with you and/or take you through the buffets. Our DS has severe peanut, tree nut and egg allergies (used to be wheat/gluten/barley too, but now he is fine after 4 long years!!!!). He is also somewhat sensitive to cow's milk (he can have it as an ingredient in a dish but not by the glass). We are provided with soy or rice milk. We do not take food from the buffets for him, but ask the chefs to prepare his plate in the back to avoid the risk of cross-contamination. DS has had many a delicious meal at WDW with his allergies. We will be taking our 8th trip with him and I will tell you that he gets more attention at WDW than he does anywhere that we eat locally.
Gluten-free, nut-free, dairy-free brownie on the left (Crystal Palace) and ditto for the Mickey waffles on the right (Cape May-Beach Club).