Thank you!
We're taking liberties with the source material right?
Why is it okay to change race and blood relations but not the age dynamics?
1: It's not a matter of okay, it's a matter of what works for the narrative in this instance.
2: Because changing the age dynamics changes the personalities and relationships of the characters, while changing race and blood relations does not. They aren't comparable.
Why can't Johnny be the older brother that never matured and Sue the much younger sister that has to pick up his slack? hey, that's a fresh new take on the characters!!!
That… would actually be interesting. I'd be totally cool with that.
Saying one thing is okay because film is a different medium and artists should be allowed to take liberties, while at the same time saying other changes aren't okay because they don't fit "the story" (a story which can be anything you want once you start deviating from the source material) well that's just trying to have your cake and eat it too. You can't play both sides.
I'm not playing both sides. Not all changes are equal. Not all changes fundamentally alter the way the character has to be portrayed.
Listen, it's not like I don't have limits. I would not, in fact, consider a film that was called the Fantastic Four but was just The Shawshank Redemption to be a good FF adaptation (although I'd still consider it to be a good film). But my primary concern, essentially my only concern, is the spirit of the thing. Is what this story and these characters are
about. Taking Johnny Storm, a character who's age in part
defines him, and making him 70 would change some of what he's about. Now, I will say, maybe it would be good if it was well executed, and if it was I'd be totally open to it. But it's not my first instinct. But in the end,
Johnny Storm is not defined by being white. Casting a black actor does not fundamentally change what he's about.
To me, wether or not a change from the source material is good depends entirely on wether or not retains the
spirit of the character, and how well it furthers the goals of the film. I can't speak to the later, but casting a black man as Johnny Storm does not effect the spirit of the character one way or another.