One thing is for sure, Nate is an offensive force. If he ever 'figures out' that he needs to play defense and puts forth the effort that most agree he has, it will make a huge difference in his future paycheck. He will be a mid level exception guy at most if he plays no defense IMO.
I dont think he will even approach Ben Gordon salary numbers. He is the closest comparison in recent players I can find from a scorer, at the same size and position standpoint.
No reason Nate can't be an on the ball absolute pest with his physical abilities. He needs to be in a system that maximizes his use on the perimeter as a pressure guy. He is gonna get posted up once in a while, that is where help has to be available as much as possible.