See the problem with having an Unpure and a Pure clan line is that no one in the clan is 100% pure and everyone in the clan is forced to, either by the clan or by their obscure location in the Village Hidden in the Sound, mate within the clan, which means, in theory, the latter members of the clan are "more Uchiha" than the initial members of the clan, bar Sasuke of course, since the gene pool has been refined to the point where it is possible for everyone to have a Sharingan while those in the initial stages have a 50-50 chance.<br/><br/>I guess we can assume that having a Sharingan would be a dominant trait among the Uchiha and natural selection would eventually sway towards everyone having the dominant Sharingan trait.<br/><br/>As for Naruto marrying Hinata, I'm not sure the Hyuuga clan would agree with that, even if Naruto was the hero of the war. I'm sure a general fling would be fine, but when it comes down to it, I see Hinata marrying a Hyuuga. She might have some say in what she wants to do since she is the princess, but in the end it'll always come down to a council of old people with ancient-dated views. We could have the optimistic ending where Hinata marries Naruto, but I imagine then that the clan would want nothing to do with her and the Hyuuga choose another among the main clan of the Hyuuga to lead the clan, starting a new era of Hyuuga.<br/><br/>I want Naruto to end up with Hinata but if I were realistically thinking, he will probably end up with Sakura.