You clearly don't like like the idea of Spidey being in the MCU, which isn't necessarily an invalid criticism. But if if he's going to be in it, his role is more of a Robin than a Batman. His powers complement the rest of the Avengers, but if he was the leader, they'd be in trouble as a crime fighting mega-group.
I don't disagree that he's a more interesting character when separated from the MCU, but after Spider-Man 3, I believe we're going to see him in the way you you seem to want to in what will likely be a Spider-Man vs. Sinister Six movie outside of the MCU (unless Feige and Sony want to go in that direction together). Ultimately, he's a street-level superhero so putting him into The Avengers I feel he's playing a bit out of his league.