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.Short Version the best Spiderman Stories are when the character is one his own.
I would love someone to name a comic Spiderman is famous for outside his own books. Most people like the Venom, Kraven and Sinister Six stuff I don't know anyone who is like my favorite Story is when Spiderman helped the Avengers.
Miss Marvel, to me is also stronger on her own. When she has villains that fit her life and make sense not some super alien she has no connection to.
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.