I figure that Starkiller just simply happens to be one of the strongest Force-sensitives of his time. With respect, I dare say there's no need for any goofy, contrived reason for it about how his training (which we really have nothing which indicates it significantly differs from regular Sith training except it started earlier in life than some) somehow made him a "Force wrecking ball" in a unique way. I also challenge ZN's idea of Starkiller lacking restraint and discipline; the man's loyalty to Vader outlived the betrayal on the Executor.
They way I see it, Starkiller just had the impressive Force potential he had simply because he did. While the fact that both of his parents were Jedi may have had something to do with it, I don't think there needs a special explanation for Starkiller's power, anymore than the likes of Sidious, Bane, Revan, or Exar Kun need one.
Regarding his ability to apparently challenge Vader and Sidious: If Luke, barely trained but using the dark side can defeat his father, then I find it reasonable that Starkiller, who has comparable power potential in addition to years of training could just manage to. Also, Sidious pretty much definitely threw the fight.
Likewise, though, I don't think Starkiller cheapens anyone else in the canon, least of all Luke Skywalker. If anything, he was the equivalent of Skywalker for his time, much like how Revan could be considered the equivalent for his time.
"Grant Allen [...] had written a book about the Evolution of the Idea of God. [...] it would be much more interesting if God wrote a book about the evolution of the idea of Grant Allen." ~ G. K. Chesterton, The Everlasting Man
Last edited by TKA-001; 08-03-2011 at 09:46 AM.