Philosophy questions - Morality & Moral Theories

I have a few questions about understanding some of the basic moral theories. Can someone please explain these to me? I don't believe there is necessarily a right or wrong answer for any of these.

Does ethical egoism mean that a moral society is impossible?

Does natural law theory necessarily require the invocation of God?

Does Utilitarianism require too much from morality?

All help is greatly appreciated.