No i'm not.now your just clutching straws
When Tobi said he would be dead, he said right now, just after he got hit by Amaterasu, you are assuming he meant that Itachi could kill him at any given time when that's not what he said.
You are assuming just because they partnered up during the massacre and agreed not to kill Sasuke that he was sacred of him.
Even if Itachi knew everything about Tobi's Kamui, it's pointless if he doesn't have the necessary abilities to counter it.