The definition and abbreviation for Potentially Hazardous Food (Time/Temperature Control for Safety Food) or PHF/TCS should be modified to drop the reference to potentially hazardous food and PHF.
Yes, as a treat apples are fine for chickens. Some will say it is best not to feed them too many apples as the seed of an apple has a small amount of arsenic in it.
Again, meat is OK. Chickens are omnivores and in the wild they will eat mice, snakes, frogs, lizards and dead carcasses (like eagles, vultures, hawks and ravens do). Much to my amazement I have seen feral chickens in Hawaii (visited with my folk once when I was young) stand around and eat road kill.