Disagreement on all fronts.
1- You are just emotionally hurt over Itach's loss. When the fact of the matter is, a 3T Sasuke broke his most powerful Moon illusion/ genjutsu /Tsukuyomi - which he was never expecting to happen so soon - and nearly killed him with Kirin. Had he not employed Yata Mirror and Totsuka Sword equipped CS, the match was finished.
He barely had time to use Totsuka on Orochimaru and seal him off. He actually died of Chakra exhaustion that pushed him to the verge of death as his body was already a frail mess. It's about time you deal with it.
2 - I agree with this. Orochimaru was more than capable of doing the deed, but he did accomplish what he came for.
3 - It was Sasori's fault, or Kishimoto endeavouring to write off a very cool character. Sakura and Chiyo should not be blamed for Sasori's poor judgement.
4 - It was never a 3 against 1 fight. Kindly reread those chapters thoroughly next time. Sasuke actually killed Danzo as many times as his unassuming ass used Izanagi. He figured out everything on his own and successfully exacted revenge when Danzo even took a hostage. Did do him good, did it - his last ditch effort, that is?
5 - False. A ninja is suppose to exploit the situation and bend it to his advantage. Unless of course you are not reading Naruto? This was extreme cunning and clever tactic on Sasuke's part. Again false. Sasuke reflected back the genjutsu, something Sharingan is known for. If you have to pick on Sasuke, do so for your solo-king as well, as he did the same with Orochimaru AND Kuranei.
What else?