Exactly this. Don't forget Danzo, he was a big problem there. So, no matter how I look at it, Itachi couldn't have stopped it all alone.
Maybe, if he told Hokage about that, but that's the story, so no :|
He was brought back without eyes, cuz both were still functioning.
He lost his eyes when he was old, and he was resurrected when he was in his prime, simple. Also, yes, he was reinforced.