@red- no I'm not. Otherwise the elders and Hiruzen wouldn't believe he could pull it off in one night. Danzo specifically came to him and told him that only he would be able to eliminate them alone prior to the coup starting. That confirms it. If Itachi didn't do it, they'd just have a civil war and it would be a group effort on the village shinobi's behalf.
@orange- Stamina? His stamina only runs out when using MS techs. He only had one MS tech back then, Tsukiyomi. He only used that on Sasuke so that he'd hate him and he could be a scapegoat. No one said that the Uchiha were fodders. However, Itachi is someone who was Anbu captain (so he's skilled in surprise and stealth assassination), grew up with them (knows their techs), and in part one he was hyped to be the most talented of that generation. Plus, it's at night. A time when it's completely unexpected and nearly all of them are sleeping. This is also the same kid who didn't even get a drop of blood on his clothing as he did this. He just needed his katana and perhaps 3-tomoe genjutsu at the max. There most likely weren't even any skirmishes bar a few minor ones. In the manga, we get a few panels of him killing adults, most are so surprised with it happening so fast that they didn't even know what hit them and didn't have time to react.
@pink- Obito himself just states that Itachi went to him to have a reason to join, he was bribing Obito. It was just a deal that allowed Obito to get sharingans and Itachi to finish quicker as well as join Akatsuki. There's not much else to it there.
@green- He was just assigned Naruto. He didn't help in any capture, in fact he didn't bother helping Kisame capture Roshi. He did help in sealing, though. But then again, any nukenin would do that and if he didn't they just find someone else. That other nukenin would be assigned to capture Naruto and would actually be for Akatsuki. If Itachi hadn't joined, this series would have taken a turn for the worst earlier.