Re: How about a solo Avengers franchise?
As a fanboy, I'd definitely like to see benchwarmer Avengers get their shot at some solo love, sure; but realistically, there's no reason to separate Avengers for a showcase project when they were primarily known as members of the team.
In other words, characters like Vision, Hawkeye, Hank Pym, Wasp, Wanda & Pietro, Ms. Marvel and others owe almost the entirety of their comic-book fame to being members of the Avenger franchise, *not* due to any low-sales extraneous mini-series, one-shots, or "Amazing Mystery Tales to Astonish Two-In-One" anthologies. So in all respects, these characters should likewise be introduced within the Avengers movie franchise itself.
THE COTTON AVENGERS
...They move like slick cotton on oil.