10 Ways To Get The Fantastic 4 Into The MCU (That Wouldn't Suck)
5. Use Spider-Man
Spider-Man is a science whizz among other things, and if he needs a science mentor who isn't going to grow a new arm or fly off to fight aliens, he could do a lot worse than Reed Richards.
Richards is just the man to take a young Peter Parker under his wing, and teach him some lessons about the dangers of reckless experimentation that both men inevitably ignore. Spidey could have to deal with one of Richards' experiments gone wrong, or seek Richards' help in facing a foe that is beyond him, like the invasion of New York by the alien H'Mojen that forced one of the comic book team-ups between Spidey and the FF.
Alternatively, Peter Parker is also an old friend of Johnny Storm in the comics continuity, so the FF have a natural way into Spider-Man's movie universe. A celebrated early moment in Spider-Man's career saw him applying to join the FF, but refusing after asking how much the job paid and being told the answer was zero. Spidey does joins the Fantastic Four in later years after Johnny Storm's death.
A season with the FF could teach Spider-Man one of those lessons about power and responsibility so important to the character, as well, as helping populate Spidey's corner of the universe with its own clutch of Marvel heroes.