He likes to eat off your hands because he likes your pampering, it's a psychological thing not necessarily because he doesn't like the food. You can try other types of food: for a young dog still growing Medi-Cal Preventive is an excellent diet for large types of dogs, you can get it from your vet's office.
The color of his nose is genetic, it's perfectly normal for dogs to have different colors of noses or change color once grown up.