Eggs have protein and protein is good for dogs because they are carnivores. I believe it helps there coat look better and can relieve dry skin. the shells are high in calcium, which is good for bones (as I'm sure you know) and teeth of course.
As far as raw it is recommended because it most closely resembles what they would eat in the wild. they are canines and can handle raw, much better than they can handle grains. They get a lot more out of it. I have not done any research on it and don't plan to feed it simply because It seems like it would be expensive and I'm afraid I will do it wrong, plus it seems time consuming. If you can do research on it then you can ee if it is right for you and your dogs. Others who have fed raw can probably give you more info and raw benefits.