I believe that punching power is more about proper form than anything else. It'd explain why one guy can take someone's head off with a right hand, but can hardly knock over a coat rack with his left hook. It's about quickly getting the momentum of one's body into the fist at point of impact.

Any beginner can learn to punch harder, there's no question about it. On a different note, can a guy like Pernell Whittaker become a puncher? It's very unlikely. There are habits, or better yet as Scrap put it, "psychodynamics" which make changing how one fights difficult as it's ingrained into the muscle memory. How would you overcome this? You'd have to ask Scrap, that's his field of expertise.