Can someone tell me if it will be a problem to get candy and then go on rides? Is it an open bag where candy will fly out? Should we bring a separate backpack? My son is allergic to peanuts and I believe I read we can go to guest service before party and trade in the bag they give him for a special one so the cast members will know to give him peanut free candy-can anyone confirm this and procedure? Thanks-so excited for our first party!