I like Nameless Fred and Mr Gump's ideas the most, mainly because the flaws aren't as apparent as the other ones. I think I favor the "longer swooper wins" idea a little bit more, because obviously that person has expended more ki and, like someone earlier had said, whoever uses the most energy should be able to get the hit.
But I also really like the idea of both players being knocked back (simul-hits are somewhat a staple of dragonball z's bigger battles, aren't they?) when they both have a similar swoop time & energy consumption (and the window should be medium, not too big and not too small of a gap).
Sonic, I really don't like your suggestion for a simple reason: it rewards playing sloppily. I am ALWAYS recharging my ki as much as I can so I can get maximum swoop/teleport/beaming capabilities. So you mean to tell me that you are going to punish me for conserving my ki by making some careless tele-whore/kame-whore win a head on attack every time?
It would be different if it was dangerous but as long as he is within a swoop's worth of ki remaining, he will be unhittable by careful, ki-conserving players like myself. The thing is, the whole game encourages KEEPING YOUR KI HIGH. When you get into a struggle it can mean life and death; when you need to finish off an opponent, it can also be an emergency. So I lose those capabilities in order to get the hit...and whoever swoops more will win, because they lose ki from swooping.
It would lamerize melee. You'd have two guys trying to fight and deliberately not recharging, and four swoops in, one of them begins to plummet to the earth and descends, and then the other guy POUNDS HIM into the ground.
I have an idea...it's taking shape in my mind now, but I'm work, and I can't give the details of it now. Talk later.