Where did it say they were adapting the 616 FF for this movie? No where by my recollection. It's an adaptation ordered by Hollywood. Do you think they care what the fans want? They are not going to make a straight adaptation.
The first FF wasn't a pure 616 adaptation of the FF mythos. Tim Story was against Doctor Doom using robots or learning black magic. So he made him a mutant like the rest of the Four. The first FF didn't fail because it wasn't a pure adaptation of the classic works. It failed because the director lacked vision and was certain he would get a sequel to ramp up the action after Rise of the Silver Surfer. Galactus a giant f*cking cloud?! Give me a break. The same things can be said about Ang Lee's Hulk, Daredevil, Elektra, Ghost Rider, Green Lantern and Superman Returns. They didn't fail because they weren't faithful to the source. They failed because they were movies audiences didn't want to pay to see over and over.
The movies are not beholden to the canon of the comics. Again, look at X-Men and Avengers. Where Avengers' Quicksilver and Scarlet Witch are called "miracles" instead of mutants and Magneto is not their father like in the comics. While X-Men's Quicksilver and Wanda are not twins and Piettro is the same age as Erik and Charles in the 60's. The comics are only there as a blureprint source of information for a film adaptation. They are not rigid guidelines for film creators to follow. Johnny Storm is a character, Michael B Jordan is an actor. An actor's job is to make us (the audience) believe he is that character on screen. We don't know what Jordan may bring to the role. He may knock it out of the park. Chris Evans wasn't bad, but the material he was served with didn't help him or the movie.
Galactus is a shapeless entity who takes on an appearance influenced by the inhabitants of each new planet, so seeing him as a cloud traveling to space towards Earth is not anything, not to mention that they added a silhouette of his comic shape in the movie. Ang Lee's Hulk was just bad all around, writing, effects, cast and Daredevil failed because people thought it was fun to mock Affleck, Elektra fell into that trap being a spin off from Daredevil. I am glad you brought DD up though because in it they cast Michael Clark Duncan as kingpin, now let's be honest he's the only actor who could play Kingpin without any visual aid, aside from that it and Elektra were some of the most literal adaptations they made.
Besides the Hulk and Superman Returns(never watched it) the movies you mentioned were some of the more faithful adaptations has put out and the fact they didn't do as well as others like Avengers means two things. 1. Studios do better when they alter a comic movie to target a general audience rather than cater to die hard fans and 2. Because they do better they will continue doing it this way.
Speaking of the Avengers though, and since you brought up Wanda and Pietro, that can be answered in a simple(political) way. Fox owns the X-Men franchise so Marvel can not use any mutant likeness in their movies which is why they are disregarding the familial relation between Wanda/Pietro and Magneto(Which is absolute bullshit)
Now obviously the Xmen franchise has had some inconsistencies, such as Alex Summers existing before Scott Summers let alone paling around with young Xavier and Magneto, and other movies as well, but just because they got away with it in the past doesn't justify it's continued practice. As for Michael B. Jordan, he's a fine actor I liked him in "That Awkward Moment" and I know he's cast as the new Torch but I'm not talking about him. You keep mentioning his name, he's not relevant to my argument. They could have cast Kevin Hart or Denzel Washington or whoever, my problem isn't with the choice of actor it's the change. I'd be just as upset if they decided to make the Torch female or disabled or an alien.
