instar: most animals that eat full bodied prey - snakes, crocs, owls, etc etc gain important nutrients and vitamins from it (ie. the feathers or fur or bones) yes. if you need to know exactly what they are, i can find out for you if you like
They are not viewed as 'objects'. I have a passion for my reptiles, I look after them very well, a number of people have seen part of my collection here, including Tenille, and I highly doubt they'll have anything bad to say about it.
I just don't delude myself into thinking it's natural. My enclosures are set up to look semi-realistic, but the truth is I keep an animal that has a home range bigger than most suburbs in a 4x2x2 (or whatever) enclosure. Some of them even have names, and I do what is best for them in captivity, not what is best for them in the wild.