Does the FF need them? I say YES!
Here are my ideas:
1. Thing: It will be revealed that after Secret Wars (where he became the great wall of battleworld) that Ben has always been able to influence his mass but never really utilized that ability. I'd have Ben be able to increase his mass to become stronger and play with the heavy hitters. It can only last short term due to the strain on his body. His regular form would still be his default but I'd add a smaller form where his rocky epidermis is super dense and it would be very difficult to seriously hurt him but the trade off would be decrease in strength.
2. Johnny: building on Reverend Meteor's idea of having Johnny burn a blue flame, why not give him the whole spectrum? Each color would have different effects and I'd reveal that the color also effects his personality. Johnny has been a jerk and a hot head over the years because he's constantly burned red. Perhaps blue would be soothing and calm him down.
3. Sue: I'd remove the almost-telekinetic powers. I know a lot of folks might hate that as it takes away a lot of the power that writers like Byrne gave her, but hear me out. She's still be able to become invisible, project force fields, etc. What I'd add is the ability to "see the unseen". Why is Sue always so intuitive? Because she can sense what normal people cannot. While not a mind reader she would be skilled at sensing what people are hiding or keeping hidden. Furthermore she could see or sense invisible portals or gateways to other dimensions. I'd also give her true invisibility, undetectable by technology. She'd be much more of a stealth character.
4. Reed: the hardest to re-imagine. I'd probably have him lose his stretching powers altogether. His real power is his mind. Maybe it's time for an de-powered I'm sure Reed could really turn his costume into a high-tech device, competing with Stark and Doom. I don't know, Reed's tough.
5. Kids: make Franklin 11 or 12 slowly developing his powers. Stop with the universe creating, it's annoying. Valeria: just a normal kid, no big brain.
Everyone else in the MU has had power upgrades, second mutations, etc. The FF need to keep up.
I agree with many of these ideas, almost all of which we've posted at one point or another.
1. Ben - Super durability, near Hulk Strength. The Hulk hates fighting him because he can't put him down. He doesn't always beat Ben and loses due to tiring out trying to hurt Ben.
2. Johnny - I have also mentioned the heat absorbing idea. Less focus on flame, more on mastery of heat energy control. That would show growth in his powers.
3. Sue - I like Sue as the powerful one. Keep her as is, IMO, with maybe only allowing external use of her powers. No more force bubbles inside people's bodies.
4. Reed - Bring back battle Reed with more use of his stretching in creative ways, combined with tech
4. Kids - Franklin must grow up, but powers must be limited. He can't be a god. Otherwise, send him off to live with Celestials.
5.Valeria = Batman (no more Uncle Doom nonsense)