Re: Sasuke and rinnegan.
To be honest, I don't think Tobi needs Sasuke with the Rinnegan anymore.
I actually don't understand what Tobi has to do with Sasuke either. At first, he was a promising ally/pawn, but now that things have come to an end (with them being on the verge of Tsuki no Me) I don't see what role he expects Sasuke to play.
Regarding Tobi's quotes back in mangas 450 and 453... There are a couple of possibilities.
First of all, remember that when Nagato died and Konan left, they were some people short for the bijuu sealing team.
Tobi directly refers to Konan's abscence while first bringing up Sasuke to be synced in chapter 450.
After that, he seems to actually be talking about giving Sasuke the Rinnegan, in 453. Because Zetsu mentions him to have accounted the possibility of Nagato's death.
I have a weird feeling that Rinne Tensei is something like Kotoamatsukami or Izanagi... Otherwise why would Tobi state that the technique was supposed to be used solely for him? He could have just stated that Nagato went off and killed himself betraying their plan. It seems as if it has a limited use or maybe a time limit.
If it wasn't so, I guess that Nagato would have revived Yahiko after he learned about it. He was saving it for Madara as a result of some major manipulation via Tobi (supposedly Madara to Nagato) although we don't know the details.
Actually, I just thought of something!
It seemed weird to me when Tobi just implanted a single Rinnegan. I always thought that it was because he still wanted his S/T jutsu and a single Rinnegan would be enough. But now that I think about it, he didn't know of Kabuto's plan to Edo Tensei Madara back then. He found out straight after he acquired the eye.
What if Tobi was actually saving the other Rinnegan for Sasuke? So he could somehow manipulate him into reviving Madara? Huh, it feels like a puzzle suddenly clicked.
Anyways, I think that Tobi did intend to give Sasuke the Rinnegan at some point, but after seing that Madara was revived via Edo Tensei there wasn't any need for it. :shrug: