Sasuke could definitely use some lessons in tact, common courtesy and respect, but at the same time he had no one to learn those things from. He was on his own after Itachi murdered his family. He went from a child who knew what love was to a child who was betrayed by the brother he idolized. His one goal became revenge and I guess he decided no one was going to be let in after that so he could not be betrayed again. I don't think he knows how to connect to people anymore. Maybe he still doesn't want to. In some ways his situation was tougher than Naruto's because he had a family he loved and who loved him and he lost that. Naruto never had that love to begin with. Although I do believe Naruto being a jinchuriki was worse. Sasuke had known what it was like to be valued and loved. Naruto only knew that people feared and disdained him.
Before everyone starts bashing, I'm not a Sasuke fan, but behaviors are learned and he had no one to learn those things from after his family was gone. He and Naruto seemed to be left to themselves when they weren't in the academy or training. I'm not making excuses, just stating facts. Parents are usually where you get your social skills from and are the people who teach you right from wrong. Both of them lived in apartment on their own when not in school or on missions.
Sasuke has a point when he says they have to focus on Kaguya. They will not defeat Kaguya if Naruto is constantly rescuing Sakura. Kakashi needs to tell Naruto that he will focus on keeping Sakura and Obito safe while Naruto does what he has to do. While I believe that Kakashi can be helpful with strategy, his and Sakura's presence is distracting Naruto. While Naruto did say he agreed with what Sasuke was saying, I cannot see Naruto letting them die.
I don't know what Sakura's problem is but she is as useless as unconscious Obito right now. The least she could do is try to heal him so Kakashi doesn't have to haul him around anymore.