Well, right offhand, I don't have a problem with players playing any race within reason. I do have a few sagas planned but I like story and player driven games. Roshi would likely be able to train with on Earth. King Kai may be an option but I plan on the Dragon Balls being mostly forgotten by this time. As for power levels, they will be much lower than the max seen in the Dragonball universe. Starting out, most races should be a thousand or lower, exceptions being the Arcosians and Makaioshin. Sorry for the shorter post and lack of in depth information, not at my computer right now.