Honestly said I don't think he would've become chunin. The problem wasn't only that the 3th died, but also that the Leaf Village almost was destroyed, even if the 3th had survived the attack.
And even if there was no attack, Naruto showed karakter and skill in his match, but it were all individual skills. While Shikamaru uses his brain and was perfectly capable too lead a squad, Naruto was still way to rash. He would probarly send his team to death with his attitude.
However that's at this point not the case anymore, especially in the battle with pain he showed that he can easily handle things now.