Julian McMahon, who plays Doctor Doom, suggested that metal staples be used to help stitch the scar at the beginning of his transformation. This comes from McMahon's experience playing a cosmetic surgeon on Nip/Tuck, making it also a subtle Actor Allusion.
Ioan Gruffudd suggested that Reed constantly be taking notes.
Chris Evans wasn't so crazy about working on the film either.
Doug Jones didn't think highly of the film either, particularly director Tim Story.
Disowned Adaptation: While Stan Lee loved Michael Chiklis' performance as the Thing, he was not a fan of how the films portrayed Dr. Doom, as he felt Victor was changed too much from his depiction in the comics.
Doing It for the Art: One of Chiklis' requirements for accepting the role of the Thing was that his character would be make-up based, rather than the CGI everyone else had previously assumed. This meant that Chiklis insisted upon hours of application and wearing heavy, uncomfortable makeup, over the option that would have allowed him to earn the same money in significantly less time simply by voice acting. Why? Because Chiklis was a fan who knew that underneath the rock skin, Ben Grimm's still a human being, and this was best shown by having his actor go through the same thing. The production team thought that Chiklis would have to ADR his lines due to the heavy prosthetics and oversized teeth he'd have to wear. Instead, he spent hours reading to his children while wearing the teeth until he became fully intelligible. Once again, it was because Chiklis felt that being able to perform in the moment with his co-stars was best way to convey the character of Ben Grimm rather than having to perform the part in a booth. Apparently, Chiklis' wife came by the set unexpectedly one day to see him. He was in the full body suit and makeup at the time, and she was totally unprepared for seeing him like that. She found it so distressing that she had to be escorted from the set in order to compose herself. Itworked.
Dyeing for Your Art: Jessica Alba dyed her hair blonde for the first film, but wore a wig for the second.
Follow the Leader: This film was made after the success of Spider-Man. It goes for a similarly lighthearted tone and there's more than a passing resembling between Dr. Doom's story-arc from this film and Norman Osborn's from that one.
Meaningful Release Date: It was originally supposed to be released on July 4, 2005, and early trailers played this up. However, its release date was shifted to four days later.
Promoted Fanboy: Michael Chiklis has been a comic book fan since he was a kid. Guess which one was his favorite.
Technology Marches On: In the second movie Reed is shown using a very clunky looking ultraportable, a type of computer design that looked dated within a couple of years of the movie's release due to netbooks, smartphones, tablets and ultrabooks.
Throw It In!: Chris Evans improvised most of his dialogue in the first movie, such as the "Aw, look — she's kissing him.", which fits seamlessly in the scene as for the benefit of Alicia, who was standing right next to him (she's blind).
Michael Chabon unsuccessfully pitched a story idea which was to be set in an Alternate History that, tonally, "was forever November 21st, 1963" and, plot-wise, was to involve Doctor Doom travelling back in time to assassinate a key world figure in order to remake the world into a grim dystopia that was pretty much the real world. Soviet agents were also going to be involved somehow.
Had Fox not rebooted the franchise a third time, they could've made a third film in this series, as the cast was signed on for a three-picture deal, and director Tim Story was interested in making said film. Among possible/planned developments for the film were:
Alicia Masters would've had more screentime, and according to Chiklis, her relationship with Ben would've had a bigger focus.
Julian McMahon would've returned as Dr. Doom, having been signed on for a 3-picture deal (like the rest of the cast). Whether he would've taken the role of Big Bad a third time is unknown.
Jessica Alba expressed interest in introducing Franklin Storm.
Beau Garret wished to return as Frankie Raye (Johnny's girlfriend).
The late Don Payne (writer of Rise of the Silver Surfer, who would later go on to write Thor: The Dark World) mentioned that while he never discussed a sequel, he did have a love for the Inhumans, the Skrulls, the Puppet Master, Annihilus, and the Negative Zone. Combined with the aforementioned statement about Alicia having more screentime, it's likely that the third film would've featured The Puppet Master (her father, and a longtime villain of the Four) in some capacity. Though it's unclear if the Puppet Master would also have been black, since he remained white in the 2005 video game adaptation.
For that matter, Story has said he would've been up for directing not just a third film, but a fourth film as well. It's likely because Fox felt that a third Story Fantastic 4 movie wouldn't be worth the investment that led them to reboot the franchise and give it to Josh Trank (ironically, his film ended up being a Box Office Bomb).
Nick Fury was originally planned to be in Rise of the Silver Surfer, but Fox eventually did not want to pay more money to get the film rights for the chraracter, so General Hager was made instead; however, some of Fury's lines from Ultimate Destruction #3 were used for this character.