Could The Uchiha Clan Have Taken Over The Leaf Village If Itachi Didn't Slaughter Them?

Can't say since every other Uchiha except Itachi is featless. Maybe Shisui by statements. Also, another thing to remember is that not every Uchiha awakened the Sharingan.

So, no, The clan couldn't have taken out that many named characters when most of them were fodders.

the mere fact that itachi as a 13 year old with a newly awaken magekyou could slaughter them means that Sarutobi, Danzo and Anbu, Kakashi, Gai, etc would of killed them even worse

Itachi was too weak to change the outcome of the Uchiha Clan, if he was as strong as Madara he could of just kill the 3rd hokage or anyone that says otherwise and konoha would have to forcefully withdraw their hate to the uchiha clan or else and he could have forcefully suppress his clan via deterrence of his power, unfortunately itachi was to young and weak and even with his power as a 21 year old is not enough to face of against the super powers of KOnoha being Jiraiya, Tsunade, sarutobi, Danzo and more, so itachi knowing the his clan stood no chance and if a war did start then Sasuke and all uchiha clan members him included would of gotten killed so the only choice the weak have is to personally kill his family so sasuke can survive and personally make himself the enemy so konoha villagers dont see the higher ups as monsters.

Power is the only language in the world of Naruto, the weak have no say

With Kakashi, Hiruzen, Danzo, Guy, Ino-Shika-Cho, etc., hell no

Nope, that clan was dead no matter what. Danzo is awful but he was right in killing the rebels to prevent a civil war that could have killed a lot more. He just went overkill and ordered the entire clan executed.

@reaverlation: Kakashi at that point is fodder to the likes of Itachi & Shisui. same with Guy. Ino-Shika-Cho aren't even a factor

the only one who's a legit threat is Sarutobi (since Shisui is alive & well for the purpose of this thread so Danzo doesn't have his eye)