Re: Itachis sicknes
Well I have two theories, sorry if anyone mentioned them before, but after reading some of the post I wanted to put my opinion in.
One theory about the illness it is a "punishment" or a "curse" for killing his clan. I am not saying that someone did it to him, but it is the consequence to his actions.
Second theory. This one is a long shot, but if you bare with me you might just be crazy enough to agree with me. We know Orochimaru has come up with a jutsu that lets him take on a new body. We also know he was once part of the Akatsuki. Maybe Madara, whose face we have not seen, needs this ability to survive; thus, Orochimaru might have been added to the Akatsuki so Madara could copy the technique with his sharigan when Orochimaru found out how to do it. Now this is where Itachi comes in. Madara obviously is going to want another Uchiha because he needs to be able to control the tailed beasts rights? So that narrows it down to Itachi and Sasuke; at the time he probably didn't know of Sasuke's survival and settled with Itachi, so he kept him close. Once Itachi died his only option is Sasuke and that is probably why he is with him. Now for the illness. If Itachi and Kimimaru have the same illness than they were probably failed experiments. Now that Orochimaru has "perfected" his jutsu all Madara needs to do is copy it.
Anyways it is a long story, but I think there is more to Orochimaru's jutsu than what we have seen.
So That is my far fetch idea!