I think there is much tha Kurama could show/teach Naruto. Imagine if they get past this battle, and Naruto can freely give chakra to anyone he wants to. BTW he should hurryup and share Chakra with Gai (the guy is very useful, no pun intended).
I can see how Naruto could easily grow into a Sage of six paths as he develops and ramps up his physical life giving energies, but he still lacks the spiritual element, and I am not a fan of NaruSasuke fusion.
Perhaps the SO6P's prophesy regarding Naruto as a successor can be fulfilled without the need for him to complete becoming a Sage of six paths. All the Sage said essentially is that the Bijuu will be inside someone else, and that he would guide them to a better path.
BTW, Unless there is a Fragment of the Ichibi still inside Gaara, then somehow, Naruto mayl have to enter inside the Juubi and break off the piece needed.