Sasuke's execution style is perfect for ANBU leadership. He doesn't follow orders but as an ANBU leader he doesn't need to, he controls the whole ANBU and acts on his own terms as long as they don't disrupt Konoha's relationship with other villages. As I mentioned, Danzo was never taking orders from Hiruzen, he only asked for consent when it was something really important like the Uchiha massacre.
Sasuke isn't the same angry kid we saw at Kage Summit, he's on good terms with Naruto and he's aware of what happened to Madara and Hashirama when they disagreed with each other. Both Naruto and Sasuke share the same goals, they don't want another war.
Danzo was responsible for Uchiha clan's death, logically Sasuke should be ANBU leader and make sure that such a decision is never made again.
Itachi was a member of ANBU so it would make sense for Sasuke to follow in his brother's footsteps.