1) Pink Ranger, noted
2) Indeed, Charl. No one has to be politically correct, but I trust that we all possess sufficient common sense to know when we are saying something that can easily be construed as offensive.
3) This is a photo of the Hodgson twins.
They are biological sisters whom have parents that are each half Black and half White. The Punnett Square demonstrates Mendelian inheritance and how one may arrive at such an occurrence with seemingly disparate organisms that share the same parents.
Given that the Fantastic Four is already science-fantasy, it would not be a far stretch at all to introduce actual science to explain a very real phenomenon. Even then, why would it matter if Johnny were adopted instead? Would that make Sue any less his sister? Would it make them have less familial love? Why do people struggle with the acceptance of blended families? This trend of thought has far wider reaching and poignant implications than the simple casting of a Hollywood film.
4) The only prominent Black superheroes aside from Storm are Blade and Spawn. Blade had a good run and the Spawn film was white washed all over the place. Marvel is currently working on a Black Panther feature length for theatrical release as well as a Luke Cage solo series for Netflix. Black superheroes are gaining exposure, but we all know that aside from Storm and Blade, Black superheroes are virtually an unknown quantity.
5) Michael B. Jordan is present because the director already worked with him on Chronicle. It's the same as the fact that Tom Hardy and Michael Cain (among others) pop up in multiple Nolan films or how Johnny Depp appears in multiple films by Tim Burton. When a director and actor form a solid working relationship, that tends to be an enduring relationship. I believe that Michael B. Jordan's casting is more about that particular dynamic than it is about any political agenda for diversity. With that said...
6) Why do people cry about consanguinity between Sue and Johnny yet say nothing when The Dark Knight Rises features an Irish man playing an Arab whose Arab daughter is played by a French woman? No one bothered to question that or complain about needing to believe in that relationship. So why is it suddenly an issue when it involves a Black man having a White sister? Oh, hey Chairy, did someone just say the secret word? HYPOCRISY! YAY!