Wow, probably the best thread I've ever read. Truly amazing ... +REP.
I don't know, if it was stated before, but I think Obito saying to Naruto " Once I was exactly like you " (something along these lines ) is another big hint, why Tobi really can be Obito.
I think Kishi wants to show us, how Naruto could have been, if he had no friends ( because, of course, Obito lost everything he lived for, his friends, his love and the goals, he wanted to achieve ), how the pain he suffered turned him into an evil monster with cruel ideals.
I really start to believe, that he is Obito, but I also believe, that there was somebody else who took the name of "Tobi", before Obito took this part and carried on the name of "No One".
I kinda believe it's strange, that we never have seen Tobi using S/T Jutsu, before Obito was born or got crushed and reappeard about 13 years later. For me, this is another hint, that Tobi might actually be just a name and that there is the possibility, that, in the past, there was somebody else who called himself "Tobi". The only logicial conclusion is Madara Uchiha, in my opinion. It
was possible, that he was alive back then, and that is the reason he never used S/T Jutsu, because, of course, it's not the special ability he gained - It's Obitos special ability. ( Probably I will make a thread about this )
But, beside Obito/Tobi:
I feel soooo sorry for Kakashi. He suffered so much pain, lost his teammates, thinks he lost his best friend and yet, he stands there with his head up and trying to be there for Naruto and Sakura, after he was not able to save Sasuke.
And now? Yes, he faces his so called dead best-friend and
has to fight him to save the world. So sad.
Kishi, why? Why do you f**k up Kakashi so much?

Poor Kakashi.
Nevertheless, Kishi is truly amazing. Flipping tables like this is just... wow.