One of the unique aspects about Hopper is that he is not a human, he's a wolf. The narrative tries hard to make this clear, I believe--they have their own set of morals different from ours, and RJ/Sanderson give us hints here and there at how different their world is to ours. Sure, by human standards, Hopper is a homicidal maniac--I completely agree with you. By wolf standards, he's just, well, a wolf.

I don't blame Hopper for thinking and doing as he does--we don't say a Lion is a "terrible animal" if it attacks a gazelle--it's just how lions are. But we CAN blame Perrin for allowing Hopper's wolf-mentality to guide Perrin into performing acts that are undoubtedly maniacal by human standards. The Pattern may want Perrin to accept his wolf brothers, but he should only use them as a tool; they cannot inform his judgment.

IMO, the hammer and the axe represent more than the builder/destroyer; they also represent his constant struggle for humanity against the insanity of the wolves. I hope he plants himself firmly back in the world of man to keep from losing his mind.