Itachi hesitated to attack Jiraiya because he knew it would bring about too much attention, heck Gai was already there. And he thought twice about fighting Gai. Why? Because he was already pretty weakened from using the sharingan technique in both scenarios. Last thing he needed was all of konoha on his ass, and the series Naruto favors strategy over raw power. I mean that kunai is just as lethal in a genins hands, but skill, strategy and experience is what seperates things. (Example: You'd never see anyone take a kick to the neck without flinching because of a silly power level number)

Jiraiya was poisoned give him a break, orochimaru had no arms but his legs work. While I agree Katsyu isnt as cool as Gamabunta, she's not too useless. Both of them got into tight spots, however it was just Tsunade bailing Gamabunta out rather than Katsyu doing it (she's a slug after all). Oh and of course orochimaru is the strongest, they mention it in 65-66. They say that he wasn't like before, because he's in a younger body, he could take more punishment and last longer than the other two. Using youth as an advantage.