humm, I seeOk, first up:
Madara has been shown to fight seriously about twice, once this is what happened:
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And another time :
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On both occasions he was forced to give up an arm, not exactly what you'd expect from someone who is to be considered the ultimate villain. Yes, i am aware what the 4th hokage said, but that was probably not referring to Madara's own fighting abilities per se, but rather about his capability to cause damage by using what you could call a proxy weapon. 16 years ago that weapon was the kyuubi, right now its Sasuke. Remember, Madara has himself said that he is a shell of his former self, one eye trasplant i do not think will change this that much.
About your Itachi refernce, same reasons. Madara's knowledge was/is his weapon, acquired over the years and Itachi knew this. Thats why he knew he'd find a way to manipulate Sasuke from his years of experience with people in such situations(remember how he got Kisame to join?) I still stand by what i said, that Sasuke is the main villain as far as the major fighting opponent for Naruto is concerned. Madara is more of a strategic and someone with extensive knowledge who can set things in motion, but from the evidence of the manga in this time line i conclude that attacking from the shadows, behind the scenes is the role he is meant to play. I wouyld'nt be surprised if kishi were to make Sasuke kill him at some future pont, of course this will only happen if Sasuke were to inherit his ambitions and plans ass well.
Peace.
tell me dude whats Madara's final goal? I'll give you hint not moon eye, thats the tip of the iceberg.