A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
Yes but the fourth probably sealed the kyuubi in Naruto because he was the only child with enough chakra to suppress the kyuubi's chakra. If that were true, then even if the kyuubi was removed Naruto would still be a formidable ninja capable of doing 20 or 30 kagebunshins. His chakra control might improve as well allowing him to use rasengan without a kagebunshin to help.
I think that if he could do a rasengan alone, then he should be able to do a Fuuton: Rasen Shuriken with only one KB... But in the manga he always does it with two.
I don't think naruto's kekkai genkai (bloodline limit) has anything to do with haku's kekkai genkai. There is no proof that naruto uses water element (unless I haven't seen a section of the manga where it says that). I do believe naruto does have a kekkai genkai because of his father's ability. His father, who is the 4th hokage, was called the "Yellow Flash" because he had an ability to transport to a certain location in the speed of light. He was widely known for this. Although it doesn't say it is a kekkai genkai in the manga, I think it might be. If this is true, then the possibilities that Naruto learns this move is very high. Also, it must be a very good technique, maybe a technique that Sasuke won't even be able to see with his Sharingan. Also, in episode 55 or 56 of Naruto Shippuden, Yamato and Kakashi mention Light and Dark elements. Since they mentioned these elements out of nowhere, I am guessing that Naruto's other element might have something to do with light and dark elements. It might have something to do with the "Yellow Flash's" ability. Anyone like my guesstimate?
Other then that although its only speculation its still creative and who knows it could be real, I mean if you think about it the Rinnengan only was brought up a while ago, even though it was foreshadowed
i would say its a good theory tho
Naruto hasn't a Kekkei Genkai, but maybe his Bijuu has the Sharingan:
this is ridiculous everyone already knows wat narutos Kekkei Genkai is!!!!!