It would be a close fight, but Naruto is definitely stronger. Sasuke has the Ameratsu which Naruto doesn't have a real defense for. At best his chakra cloke would catch fire and he'd constantly have to release and form it to avoid being burned alive. Naruto is primarily a brute force fighter, so with Susanoo obsorbing any beast bombs and rasenshurikens, it is a simple who can outlast the other, and that's where Naruto wins. I think it would come down to both of them getting exhausted and have to resort to their most powerful close range attack that they can muster, Chidori and Rasengan (flashback). Naruto would wind up on top simply because he can take more damage and he would have more chakra to put into his Rasengan than Sasuke could put into his Chidori.
As for the teammates, I don't think that Sasuke would allow anyone to interfere in his fight with Naruto, even if he died. Additionally, since Sasuke has switched back, the above fight would likely be a friendly challenge. I think they will fight no matter what, Naruto wanted to fight Sasuke just to prove himself since the beginning, I don't think he will let that go even if he is already Hokage.