there's no question that he's an integral part of the Avengers
Unless the movie franchise simply decides that he's not. We just seemed to have a pretty successful Avengers movie without him.
Eh, that's true. I'm not really the biggest Ant-Man fan, myself, but Marvel's done such a good job with their movies so far that I'm interested to see how this one turns out.
I agree with you that it'd be nice to see another female added to the group. One positive to featuring Hank Pym as Ant-Man is that he'd most likely be packaged together with Janet van Dyne, the Wasp. But I'd like to see Ms. Marvel, too.