On History: The FF
See, I had actually come in contact with the FF previously. It was that storyline from Fantastic Four #111-112 in which the Thing has gone crazy, has a mad throw-down with the Hulk and destroys a good chunk of the city; meanwhile, Mr. Fantastic and the Human Torch are arguing about how to handle the situation, and the Invisible Girl was off in the country worrying about all of them. Everyone was dour and upset with one another, the book was oozing with negativity and pessimism. Not to mention that they weren't even fighting bad guys; they were just fighting other heroes.
After I got hooked on the comic from Byrne, I started going back to amass a collection of the previous 253 issues, as well as subscribing to the series going forward. Over the course of the decades those stories took place, there are obviously a lot of different approaches to the characters. Some made more sense than others. Some were executed via some sort of editorial fiat.
The FF teaming up with the Shogun Warriors? Probably not the best use of the team. It's the wrong genre, and there's no compelling reason for a team-up.
The FF trying to stave off an interdimensional war by fighting an alternate reality version of Johnny in space hockey gear? A bit weird with the hockey gear specifically, but an okay concept otherwise since it involves exploring other dimensions.
Having to fight off a team of witches trying to use Reed and Sue's son as key part of some ritual? A bit genre-stretching, but doable since it's rooted in protecting one's family.
Sue threatening divorce because Reed shut down her son's brain? Um, no.
The stories that always stood out as particularly bad were the ones that went too far outside the core concept. When they were treated as superheroes. When they forgot the notion of family. (Not that team members couldn't be replaced, just that they had to be incorporated into the group as family members in order to work with the concept.) When things became dour and depressing.
The team was birthed in the early 1960s amid a wave of optimisim about future, thanks to the advances of modern science. The first issue debuted only a few months after President John F. Kennedy spoke to Congress about landing a man on the moon before the end of the decade. If any comic of super-powered individuals was imbued from the start with more optimism than the Fantastic Four... well, there hasn't been, so I can't even finish that sentence.
Look, The Incredibles conclusively proved you can make a great superhero movie without an origin. If movie makers would just pick a storyline from one of the optmistic periods of the FF's comic and stick with that, we could finally get a decent FF movie. No origin is necessary. Hell, even if you wanted to include one, all it would take would be one of the characters just saying, "Back when we got bombarded with cosmic rays..."
Anyway, my point is that the core concept of the characters is what's important, and straying from that is where you run into problems. You can change up the costumes, tweak the powers around, get diverse actors to play the roles... that's all superficial fluff. It's going back to the source and recognizing the history of what worked (and what hasn't) that's important.