I really would have liked to see the newish character Gravity totally replaced with a teen Jack with the gravity powers he used as 'Jumpin' Jack.' Same age group. Same basic power (quite a bit less, actually, which makes him a bit more fun than 'loses his temper and destroys Las Vegas, killing thousands' Gravity, IMO).
Similarly, 'Molecula, Mistress of Density' had a pretty amazing power, shrinking to make herself strong and tough, or expanding into a giant gaseous form. Seeing her get hooked up by either Kymelian tech or some Earth-genius scientist who already works in that field (like Pym) with the ability to use her power on *other stuff* (I just turned this wall into a vaporous state, so we can all run through it! Oh crap, it was structural, now the building is collapsing! I just shrank the doohickey we need to get out of here, and made it nearly indestructible in the process, so the bad guys can't break it! Problem... it weighs the same, is someone really, really strong?) All sorts of whacky fun possibilities!
The oldest kid, who ended up with the 'Destroyer' power IIRC, was, IMO, the least interesting. All the angst of Sam Guthrie, zero of the gawky charm.