Re: solving of breaking the mask of tobi 100% spoiler
This is a awesome theory. Very well done with the info you had at your disposal at the time.
Although #4 seems like an invalid argument now since Tsunade thinks that Tobi is immortal.
One other thing I noticed about Tobi was that the Kyuubi recognized him, by saying "YOU!", when Tobi took control of him when kushina's seal was breaking.
This is EXTREMELY significant since the Kyuubi has been sealed up in two different Jinchuuriki's, before Naruto, for a certain amount of time. There is no way he could have gotten to know anyone else in that span of time.
From the time Madara controlled the Kyuubi these are the people the Kyuubi came into close enough contact with (in chronological order):
1. Uchiha Madara (was controlling it at the valley of the end)
2. Senju Hashirama (fought it, and probably helped seal it)
3. Uzumaki Mito (became its jinchuuriki after Madara lost it)
4. Uzumaki Kushina (became its jinchuuriki after Mito)
5. Tobi (Helps the seal break and takes control of Kyuubi)-This when tobi is recognised
6. Namekaze Minato
7. Uzumaki Naruto
8. Uchiha Sasuke
This means for Tobi to be recognized by the Kyuubi means Tobi and the Kyuubi met either before the Madara VS Hashirama battle or Tobi IS Madara.
Even if Tobi is not Madara, this would still mean that Tobi is definitely MUCH older than Kagami.