I can adhere the whole story in Naruto except the Uchiha massacre
Why confiding the mission to one ninja when facing an entire clan. What if that fails? The Uchiha will revolt immediately. What were Danzo thinking when taking this decision?
Balancing the survive of his brother and the massacre of the whole family, if I were Itachi, I would have fleed after kidnapping Sasuke, if what matters was Sasuke to survive.
Why would Tobi agree to kill the Uchihas? We know he is not Madara. He does not have really a reason.
Why would Itachi try to negotiate a deal with Tobi? It is a random dude he met for the first time. He is so suspicious, I would not trust him to keep his word especially letting the village safe.
Well, now it is over and there are other interesting things to know.
PS: if he killed the parents when they were kneeling down, I don't understand how the bodies are disposed like that