Madara will have a fight with the 1st hokage and they will both seal each other away something along the lines of it. Tobi will just get annihilated by Sasuke. Orochimaru will have the perfect mix of Senju and Uchiha dna becoming the host of the jubi. The sage of six paths was a perfect mix of senju and uchiha dna. Naruto will learn chubaku tensei and seal the jubi (full power) back into the moon.
If not, I'm keeping the same parts but the ending being Naruto lets Karama leave his body and become the guard of Konoha and seal the jubi in himself. I believe the second one might happen more because it's safer, Naruto is younger then the sage of sixthpaths thats why the sage couldnt handle the extent of sealing the jubi in himself since he was old, Naruto is young and with the jubi if anything happens to karuma he gets put under genjutsu with sharingan he can easily control the situation with the power of the jubi.
Naruto won't officially become the hokage, I mean he'll wear the same hokage cloak minato did. For the desk work I believe he'll either leave it to Sakura or Shikamaru.