[Dr Kain]

I really feel that for Marvel's MCU X-Men reboot, I'd like to see them start small with maybe just the Brotherhood of Evil Mutants. This way, they can focus on developing like 6 heroes and 3-4 villains. Then have it revealed in the post credit scene that Magneto is the founder of the Brotherhood. Save Mr Sinister for the third film.

For Fantastic Four, kick the movies off with Mole Man as the first villain. Again, bring Doom in in the credit scene.

Silver Surfer is tough because I want him to be Galactus' herald until he meets the Fantastic Four. As such, just do an origin story for him and maybe have it take place between Captain Marvel and Iron Man so that Ronan can be the main villain. This will also give them an opportunity to actually really develop Ronan into a character this time around. Third time's the charm, right?