Re: Do you think Fox will/should make a Silver Surfer film?
^ Yes it would be, on top of a Deadpool movie, more Woverine films, and maybe X-Men spinning off into X-Force. Fox can do so many cool things that people don't realize. With Surfer they can even explore the Shi'ar empire since Fox should have the rights to that and then use that as the bases for a FF/X-Men crossover film.
And I don't think that FF will be nearly as dependent on the X-Men with Fox as they would be with the Avengers at Marvel. They're going to be largely in their own corners until a crossover film way down the line. Fox is obligated to continue producing FF films so every film they put out is not going to tie right into the X-Men films, unlike if Marvel had the rights, where they can just make a film or two that ties into the Avengers and then call it a day.
I think the situation we're in right now is ideal, with Spider-Man, X-Men, and FF at different studios than Marvel. The only thing I would ask for is some little easter eggs to make it clear that they all work in the same universe, like some Stark Industries tech in Spider-Man or the term mutants being used in one of the MCU films. Other than that, it's quite fine to keep them separate and not crossover into the Avengers.