Re: naruto vs kabuto rematch...
Kabuto is about as strong as he's going to get. He's got his Edo Tensei and "that" jutsu, but he's not going to learn anymore most likely.
Naruto's not near done training (TBB, sage+RKS mode, "that" jutsu), and there's a damn good chance he could kill Kabuto as he is right now because his jutsu are all so over-packed with power.
Kabuto has Manda II, but Naruto would likely summon Ma/Pa toad (or have them summon more toads), Gamabunta, Gamakichi, etc like he did against Nagato. That fight also gave him experience against a multi-bodied opponent which Edo Tensei would be analogous to.
Kabuto is over-rated in my book. He's alive mostly because of the dirt he has on Madara rather than his prowess as a shinobi. He's also living off of the strength of Orochimaru rather than being able to develop himself to this level independently. Now, he just improved Edo Tensei by getting some of Orochimaru's chakra.
So far, Edo Tensei has failed to impress. Orochimaru with the first and second Hokage could not kill an aged Sarutobi. Now Kabuto, isn't winning the war with his Edo Tensei either. Sure he corrected the bonding issue with Zabuza et al. for now, but there's no doubt they'll be stopped.
Kabuto will be around for as long as he's useful to Madara, then Sasuke will ilkely be the one to kill him.