Is Nate Diaz better than Casey Kenney?
I think he is for sure. The two have never fought and likely never will so it could be debated.
True; Nate was booked for a showdown with Dustin Power who I believe is a world champ. 
Dustin smoked Conor McGregor in his last fight, and even tho it wasn't for the world title, it should've been, so some say and feel Dustin is the current champ.
Yes but the unfortunate news was that he was forced out of his lightweight contender bout with Nate; which was surprising 
That would have been a great fight to see too. Dustin and Nate have been missing each other in the ring in one way or another since as long as I can recall.
Yes not sure if their parts will ever cross; if it does cross that will be a good one to watch
Any fight that Nate is involved in you can bet I will be watching. Dustin too tho, he's a great one, and trains near where I reside. 
Nate has come a long way though; won the Ultimate Fighter 5
Yes he did. Fun fact about that is that Nate didn't even wanna do that show. His brother Nick Diaz pushed him to do it.