Naruto Shippuuden Episode 47

[Yukimura]

I believe it was also stated that not all Uchiha obtain the Sharingan, though that could mean not all are able to eventually activate it but all are born with the potential or it could mean some people born of two Uchiha parents just won't be able to activate it at all and some will. I don't think we've been given enough info to be sure of either.

With what we know of the First's technique it does seem like a Bloodline Limit ability because it was contained in his genetic makeup, however it could be the case that the precise mix of genetics required to make it possible only happened in the First and none of his descendants got the right gene mix to allow them to use it too, effectively making it unique to him.

EDIT @Abdula: Same thing with the Kazekage, their abilities are most likely genetically unique to their particular genetic makeup but got destroyed when they mixed genes with another person to produce offspring, that way the abilities wouldn't really fit under the definition of Bloodline Limit since it seems to imply that the technique is more likely than not to be passed down to future generations.