Hmm that would suck. Naruto finds out his family had a bloodline limit but can't acess it while he has the seal on him, and Kyuubi inside.
And I was thinking more of the whole chakra control, and fighting skill. Not spamming chakra, and shadow clones to make a super movie. I'm sure a lot of people could do Rasengan if they wanted but they have their own moves. Which is what I like about Naruto. Some people may have copies but there is a lot of different moves. Rasengan would be pointless if a bunch people were running around spamming it when Naruto does that enough himself.