A bird like that is never going to be a pet, it may show affection towards you when offering food but it is highly intelligent, highly suspicious and is unlikely to have much respect for you. Most pet birds do enjoy human contact, but parrots and birds of higher intelligence will always see you as the thing stopping him from flying free and finding a mate, and crows aren't tame and I can't really see that they ever will be.

Why don't you get involved with a raptor sanctuary or something? You would enjoy getting close to beautiful and intelligence birds in an environment thats stimulating enough for them to be happy, whilst also helping conserving the species!