One more thing! Didn't you notice that when he saved Naruto from Haku, from Orochimaru and from Itachi?
Then here's the quote, although the words are closer.
"I don't want to see anyone DIE in front of me." --Sasuke UchihaDo you remember that quote? Do you remember that when he run towards TANZAKU (IIRC) to find Naruto?
He did cared for Naruto, and DEEP INSIDE HIM, I know he still cares about Naruto, but denying it. There is such NO REASON for him to KILL Naruto, except he want to SURPASS him.
"If you think I'm just a foolish kid ruled by his emotions, that's fine. Following Itachi's path would be childish, the whispering of fools who don't know hatred. If anyone else tries to ridicule the way I live, I'll slaughter everyone they ever cared about. And then maybe they'll understand what it's like to taste… a little of my hatred." -- Sasuke Uchiha, to TOBI.NOTE: The quote above has nothing to do with the theory.
Sasuke's heart was trapped on the darkness. And it's because it's indeed painful TO SEE YOUR PARENTS die in front of you. He doesn't know anything yet. This made my speculation stronger.
"I don't look to the future any more. Only the past." -- Sasuke Uchiha, to Naruto.This quote made the theory stronger, all the usual. Next, in Part 1 he can't kill Naruto, now he wants to kill Naruto? What the hell is that?
Naruto is still stronger, all the usual. Our main character has still techniques in his sleeves. WATCH OUT!
As for SASUKE, I don't consider him as an ANTAGONIST. He is still protagonist because he's a main character as well. He also has many techniques to reveal.
SO SEEYAH for more speculations! BYE!