Itachi also killed the civilians while Obito handled the police.
No. In the anime, they show Obito kill the guards and then he disappears (he continues to kill off-screen). Itachi kills some random Police Force members in the streets. But, this is filler and should be disregarded considering Kishimoto had no influence.
In the manga, we don't see who killed who, however...
In the databook it says that the vast majority are members. So, over 50%. We can assume that they divided the clan pretty evenly. Plus, it's implied that they just went for it tbh. I doubt they specifically planned out which one of them would be going to which house and buildings. They probably just divided it into general areas and continued until it was finished.
Manga didn't specifically say he could do it own his own, and even Sasuke said as skilled as Itachi was, he couldn't take down the Leaf Police alone. Which is why he enlisted the help of who he thought was Madara, plus Obito knew he was a spy, not much to spy on, on Itachi's part.
Yes, this was the same Sasuke who thought he had won his fight within the first 40 seconds and didn't notice it was a clone until the bunshin pointed to where Itachi was sitting. And also the same Sasuke who didn't notice the fight was staged. The very same Sasuke who didn't see his brother in action bar seeing him in the forest do a few basic kunai/shuriken tricks. The same one who was 8 at the last time he saw Itachi in genuine action. :/
If the elders and Hokage who have seen Itachi in action think that he alone is enough, then he is.
He didn't want them to touch the village, that worked seeing as how he was assigned to get Naruto and he used that to his advantage... he never got Naruto when he had the chance to easily do so. It was worth it in this regard. It basically prevented Akatsuki from finishing plans sooner.
You had me until you said the bold.It would have been perfect if you didn't say that.
I know that "traitors" most often times has a negative connotation, but it doesn't have to here.
The Uchiha
are traitors to Konoha no matter how you look at it. They had their reasons for the coup, I get that.
Just as Obito and Itachi
are traitors to the Uchiha clan and their is no sugar-coating that.
It just depends on one's own perspective on who's betrayal was "worth it".