Yeah, the entirety of FFINO was bad, though I found the opening with L'il Benji and L'il Reed actually kinda charming. But it made its bones with everything after the one year time jump, which was as mind boggling awful as a superhero movie can possibly be. And that was 100% pure Kinberg.
Personally I thought the first 20 minutes or so of FFINO was good and showed promise. I liked the comradery between Teller, Jordan and the others. But then the movie steadily torpedoed after that, especially after Reed ran away the from the facility. You could literally feel that something went horribly wrong in post production and editing after the first act.
I fell asleep at the beginning, awoke to see "one year later" appear on screen and wondered how long I had been watching this movie and why it was still so boring.
If I had to guess, I'd say Trank's story was:
First Act - introduce characters
Second Act - characters open a portal go through, and explore an alien dimension where they are exposed to an environment that alters their genetic make-up.
Third Act - Characters learn to deal with their 'disabilities' and by the end they have grown and come to terms with what they are.
As Fantastic Four fans, that wouldn't have been right at all, but as a stand-alone sci-fi film, it could have been interesting and intriguing if done right.
But I suspect Kinberg and the studio said: "We can't do this. This isn't a superhero movie. We need a big battle to save the world in the third act."
But they didn't have time to create a new script and hire a new director because they were under the gun to start filming or lose the rights.
So instead of starting over, like they should have or allowing Trank to make his film, Kinberg went to Baton Rouge and started rewriting and rewriting and trying to twist that story into something that had a big battle in the third act, and that's why the third act felt so out of place and disconnected.
And during that process, Trank likely became increasingly frustrated that he wasn't able to make the film he wanted to make and that led him to withdraw and become the mess we heard about.