Naruto had to tap into the Kyuubi THREE times to TIE with Gaara.
If he hadnt of been using the Kyuubi he would have been destroyed, you cant really compare Naruto, Gaara and Sasuke.
Sasuke DOESNT have a demon, the others do.
As for pure talent without their use of demons Sasuke is the better nin

I believe that if Shukaku was released during the tournie the 3rd would have stepped in as Shukaku is 'evil' and obviously the 3rd would try to keep the peace. Its just like if Naruto released the Kyuubi completely - do you think they'd let the match go on?
Same thing goes for if Sasuke activates his cursed seal during the tournie, they'd stop the fight.

the Sharigan is no where near the same as having a demon to rely on, the sharigan CONSUMES chakra while demons give practically endless chakra.