Thanks for the help, I just need to know one more thing.
How would you store things to a client? Example: In gamefandan's server, you can do /saveme to save stats, and /loadme to load them, even if you reconnect. To my knowledge, he stores them by name. I think, if possible, it would be more efficient to save by bl_id. If you do %level = "2"; and some more code with that, it will make it so every time some one levels up, everyone else's levels would be set to that. How would you make it individual?
Also, for the relative velocity, I will look into the event mod for it.