These guys (and gals) do indeed look awesome. I especially like Lady America (it's a cool moniker and even her identity, Amanda Rogers, is a sweet name!)
I didn't notice it at first, but Ranger's right that you WAY shorted her. You take one tenth of the character's Strength (it's easy with her, so 1/10th of 60 is 6) and you cube that. So 6 x 6 x 6 = 216. Then you add 1/10 of her Endurance (which is 30, so +3 more). So 216 + 3 = 219. Then you multiply that total by half her weight. Her weight is 120 lbs., so that means you multiply it by 60. 219 x 60 = 13,140 lbs.
So she's solidly in the 2d10 category (much higher than the 540, which only got her 1d8)!
Thanks for sharing these with us; they all look like a lot of fun!
Weaknesses can be fun, too, rather than debilitating. So instead of something that paralyzes them in the middle of a fight, you can add something like Phobia: Fear of spiders, or Vulnerability: Takes triple damage from flame or heat attacks (knowing that none of the Destroyers will be exploiting this weakness). They can simply add character, nuance, and personality to the PCs, which makes them in turn a little more fun to play. And they answer the question of "how did they get so many powers?" to some players (who know the system or supers RPGs in general, as they can understand that they get a little bit more when balanced with a weakness).
Another piece of advice I've picked up from others (and which has worked well in my Con games). This is really only for Con one-shots too: give the PCs connections with each other. This adds a lot of fun and dramatic excitement to the role-playing that happens. It shouldn't be something that takes over the session, but if you can add some fun via it, it truly adds another dimension to the game. For example, two of the PCs might have an intense rivalry (but a friendly one, like Legolas and Gimli in
The Lord of the Rings). Or one character might be the uncle or aunt of another (or a step brother or cousin or whatever). Making them somewhat connected in this way can draw the characters towards each other, give them a reason to be united (especially with complete strangers) and gives them a commonality and unity that they might not otherwise have had.
Good luck with things; you're off to a great start with some really fun characters!