Re: Luke Cage introduced in Avengers 2, Hulk blasted into space
No I don't think that could work. Luke Cage could hardly out-muscle Captain America. Let alone Hulk. Hulk would smash puny Power Man.
Cage and Fury are both from New York. Harlem and NYC respectively. But I dont think they were very close friends in the comics (one being a government spy and one being private investigation).
A lot of people want to see Hulk blasted into space for one reason or the other (including myself) and I wouldn't mind seeing a world destroyed by Ultron. So those parts of your theory could be entertaining.