1) NPC's need to STOP chasing you after a certain time - not too sure what that is. Distance from spawn point, distance from player, timer without attack landing?
2) With /speed 40 on, I can outrun any spawn - yet no matter how far ahead I am, they can still hit me and do damage (reminds me of a certain SOE expansion ~cough~)
3) If you aggro, then /goto or /move, the aggroed NPC is immediately popped where you are and the fight continutes (this will not effect normal players, but likely a part of the above)
Just putting this out here so others know, we know.