Why Sasuke's character isn't "ruined"
Naruto vs. Sasuke has been in the works too long to end like this. Kishimoto would be trolling fans too much to not give us that much. While Sasuke might have decided to not let the village go to waste, I think he will also be unforgiven by many in the village. In particular the elders, who are going to be out for blood for Danzo's death. Sai might also be upset, as well as members of the K11 that are distrustful of Sasuke at best. Sakura was even ready to kill Sasuke back at their last reunion.
It'd be unbelievably bad writing for the villagers, Raikage and crew to just magically forgive Sasuke because Naruto said so. Even assuming that Tsunade does survive, she won't be able to quell the public anger against Sasuke trying to assassinate all the leaders of the ninja world and allying with the Akatsuki. I also don't think Orochimaru will get Sasuke's body, since that arc ended long ago.
Sasuke will still be angry with Naruto and the rest of them even after the war ends. He didn't "turn good" or give up on revenge, he just decided he won't let Madara end the entire world or make Itachi's sacrifice worthless. Once he hears Madara's side of the story, I predict he will turn on the Hokage and seal Hashirama, followed by Tobirama and then Orochimaru and he will deal with the Alliance while Madara fights Obito.
In the fight, I predict Naruto will die.