I really like the idea of the Supreme Kai's planet, it can make a great map
but i think i should mention that the Z sword should be gotten by whoever is strong enough to pick it up, not only Gohan
you see, Gohan is not the only one that can pull it off, he is just the one who did it, goku and vegeta for example could do it too(it's not sealed by mystic powers, it's just too heavy, that's why only the strongest ones can pick it up)
Even Goku could pick it up, he did it once while training with Gohan, remember?
so the Z sword should be there, but only someone with the level of at least 20 million can pick it up, and it will slow him down as hell(ofcourse, the more energy he got it will slow him down less)
what do you say?