Wolves don't howl at the moon, full or not. They howl to to communicate within their pack or as a greeting. Also they use it to warn other packs of their presence in their territory. Wolves are not greedy. They will however sometimes gorge themselves on a kill with up to 6 kg of meat when food had been scarce and they haven't eaten in several days.
Wolves usually eat as much as they can.
But if there is leftover meat from a kill, they may bury the meat in a cache and eat it later. It is true that some people have been attacked and killed by sick or captive wolves. There is no documented proof of anyone in North America ever having been fatally attacked by a healthy, wild wolf. Actually, the real truth is that wolves that live in the wild are afraid of people and often run away from them. There are many stories about a wolf raising a human child.