@5th: LOL for real shouldn't Naruto have wood style or Develop a new Sage justsu then. didn't Naruto had Shisui Eye in him is that Why he obtained the Six Paths.
@Galenbeta: He could have probably obtained the Rinnegan if the implanted crow (Shisui's Eye and Itachi's Chakra) would've stayed longer in him, after all, obtaining the Rinnegan is a long process.
Nagato was given the Rinnegan at a very young age but it wasn't active until he was faced with Hanzo and the Anbu.
Madara obtained the Rinnegan shortly before his death, and by then Madara was already a century year old.
Danzo couldn't activate the Rinnegan because he wasn't a direct descendant of the Senju or Uchiha, he merely had their DNA for the Izanagi usage and Shisui's Sharingan.