Well he doesn't have ray's strength, but Nick is in good shape and he's a lot lighter, so with the same technique as the larger man he would be just as fast or faster.

And as far as the clarity, he knows the basics of boxing just from watching ray throw one punch, because all of the subtle things that normal humans may look over about his form, angles of his shoulders, the way throws the punch and the way he retracts it, is an encyclopedia of knowledge to the superhuman ability to pay attention to these very tiny details. 
Plus its not like Nick has never seen a fight or a boxing match in his life prior to this, he knows the theory of how boxing works anyway, he just needed to be hit with a real life demonstration to put all that knowledge together in a cocktail of pure information and muscle memory.