He was clenching his arm when he was talking about taking his brother's eyes.....
I think this would more likely imply that he still regrets having to do that, rather than, you know, suggesting he's Obito...

Jiraiya made a theory when he was talking to the frog key that the Kyubi's attack might not have been a natural disaster... Itachi also revealed that Madara has the power to control Kyubi... finally, it's already been shown that Madara has controlled Kyubi in the past. Three key details that could suggest Madara is lying about it being a natural disaster, but then again, who knows? Maybe these details are meant to justify the advisors' suspicions towards Uchiha...

Also, to answer whoever asked about it on the previous page -- Uchiha has the power to control Kyubi, Hashirama only has the power to pacify Kyubi.