This was a good argument. Btw, not dismissing one of the points you mentioned, just putting my view on that.
When Kakashi asked Sasuke about his current dreams and how did he view T7, Naruto's reaction somewhat convinced me that he already knew what was Sasuke's dream and what T7 meant for him. His facial expressions and that '!' suggested that he knew about Sasuke's goals. It seemed like "Oh kitten! Sasuke's in a fix now. He has to tell his goals which are....evil". This goes along the fact that Naruto is always protective of Sasuke however bad he is.
Yes Naruto knows that Sasuke's dream of being Hokage is up to no good and its not evident just in 675 but also in 631,635 and when Sasuke was about to kill Obito Minato's comment , however he's not being very protective of him in here it just that he knows that he's gonna have to fight him latter but for now he needs Sasuke's help so he can protect everyone so he remains silent about it but his expressions tells you everything . Also Naruto knows that he's the only one who can fight him and in the Kage summit he made his resolve he's not gonna let Sasuke do what he wants its either change Sasuke's view thru beating the living crap out of him or they both die .