X and Y are almost 100% useless. The only thing I could imagine using them for is X Lock for knockback immunity. Z can keep you in the air if you jump and set it off, or to keep you on the ground (this could be amazingly useful PvP I'd imagine. Archers can no longer AAS you).
The MP is per-map. Every time you go through a warp it resets your MP to normal. Unlock the hack, use a potion so you have enough MP to cast your highest skill, then relock it. It's really glitchy and some skills act funny.
This wasn't a real hack release, it was more of a proof of concept for the people who claimed nothing could be done.