First of all we should be able to duel each other any time, anywhere with previously agreed upon weapons in a restricted space. But how cool would it be if there was a dueling zone in the tower - like a dojo - where players could go between missions or when they are bored to watch/participate in duels. The intercom tower voice lady could even announce when a player was tearing it up so that people just zoning in could go watch/challenge him. Also what if they added an infamy system based on duels where you gain infamy for duel streaks and unlock shaders, emblems, maybe even titles to go under your name? Players would get more infamy for defeating others with higher infamy and actually become legend....