What about transformations? Some of the transformations, like Trunks' And Vegeta's and such, look like they only belong on flat ground. You didn't mention the discrepency in that.
And I've seen swooping in the series on the ground.
I don't think it looks dumb.. but I guess it's a matter of taste.
I mean, all swooping is, really, is automatically moving forward, and faster then normally possible. But if you want to split hairs regardless, when you run with turbo, your feet move faster. The same animation could be meshed into ground swooping. Although it'd look silly, honestly the swooping would look better, but as I said, matter of taste. The team will fit to the teams' taste.
And then you'd have ground melee. Happy day!
Take it a step farther, fixing blasts via collision detection tweaking and such (I guess), maybe changing them so that a sharp angle of collision is required, otherwise the blast just glides along the ground, following it's angle, whatever it may be... (/stab in the dark) and you can fire blasts from the ground as well! YAY!
Add the cvar to disable flying and now kiddies can run around like maniacs! YAYYyyy... yy....
And if you want you can add people bouncing and skidding. That'd be just precious. But that's a whole 'nother thread, I guess.
...I just remember it being pretty fun getting on top of the highest buildings in esf_city without flying. And jumping from rooftop to rooftop... etc..