Naruto has NOT mastered the Rasengan, he merely created a creative way of performing it.

Also, I do not buy in any way that strength is the primary requirement for Hokage, on the basis of common sense. The Kages just don't engage in battle very often. We only saw the 3rd fight ONCE. And as far as we know, the 4th only fought one battle as Hokage.

I think Naruto will achieve his goal of becoming Hokage because he will eventually be fit for the role, learning patience and getting smarter (to a point). I see him becoming a bit like Jiraiya as he ages, staying eccentric and keeping his distinct personality, but developing into someone who has enough intelligence and experience to make decent decisions. Naruto will probably never reach the genius intellect of someone like Shikamaru, but it is also clear that Shikamaru will probably never reach the power that Naruto has (too troublesome!).

How do you profess to know that Orochimaru's chakra was powering the summons? It doesn't make any sense, it doesn't work that way for any other summons .. and don't say it's because they are dead, because there were LIVING sacrifices that powered the summons. It's ambiguous as best, certainly nothing to draw certainty on. The only thing you can clearly draw from it is that Oro NEEDED them, because he was too weak to face the 3rd on his own merits, he felt he had to cheat.

Again, I don't know how many times I'm going to have to say this .. strength is NOT the defining requirement for being Hokage, strength is what the position HAS. If Konohamaru was appointed hokage instead of Tsunade (yeah, I know .. LOL) .. then HE would be the strongest person in Konoha. Not because he can fight anyone, but because he is IN CHARGE, he COMMANDS the village and all of its powers. Fighting is very secondary to the position.

From everything I've seen ... Orochimaru = very cunning and clever, but physically weak in combat .. he relies on tricks, traps, and knowledge of jutsu to survive. The 4th seems to have been a Naruto type, relies on his determination/chakra combined with a few great jutsu to overcome his obstacles.

If you want to insist on simple combat strength as being the primary requirement for Hokage, I just don't know what to tell you, other than that's pretty silly.