Animecivil,
Actually I was not concerned at all about an enenmy staying at rooftop level to shoot at the player as that should be posible - if its not its a disapointment. But your observation about the enemy jumping straight off the top of a building and heading directly towards the player gets to the basic the point of the question.
Obviously if we were on top a 10 story building and wanted to get to someone below we would not jump off the roof but make a way to a path of elevator to get down - thats the point.
I was wanted to know if enemy AI/pathfinding was capable of ensuring an enemy does exactly that - i.e. ignores the player and chooses the human like method of using brains and find/use the stairs en-route to the player.
DavidT has suggested that this is indeed the case - lets hope so.
I have a number of levels where something more than rudementary AI would be more than helpful - hopefully thats what we will get, albeit with perhaps a measure of FPI scripting effort.