Nah, it's just plain not possible to keep track of skills due to how much of a team game NS is. It would never work off of kill/deaths, damage dealt to different lifeforms with various weapons would get to complicated. Aswell as there being different types of skills other than your basic aiming. Like me, I'm not that great at aiming, but im a l33t ninja (as much as I hate them, I do it :p ) and ninja skills can be extremely powerful. An example being my Holy Grail of Ninjaing, a game on tanith once. 3rd hive was taken and began going up, all the marines assumed we lost, I began ninjaing, and ended up winning with 3 ninja phase shotgun rushes in a row, all because I know how to sneak.
