Re: Misconception about Tobi giving Nagato the Rinnegan.
Tobi was not the one that gave Nagato his rinnegan..why? because Nagato is older than Tobi and he had the rinnegan back before obito would have even been born.
Understand that a big part of Obitos plan was to pretend to be Madara, why? Because he needed to strike fear and doubt into people's minds, without the name Madara Uchiha he would not have been a big enough threat to start a war.
Not everyone in the Akatsuki even knew Tobi was pretending to be Madara, what I think is that Madara somehow played a hand in the extermination of the Uchiha clan..I don't know how but he must have been the one acting as Tobi that night. It's a mystery because we didn't get to see if the long haired masked man even had a sharingan, so a lot has yet to be explained.
However, it was Obito pretending to me Madara the whole time so that he could start the war.