TRAIN! A cry heard all over Norrath and one of my least favorite parts of the game.
I would like to suggest that you consider reducing the existing Aggro Radius of mobs. This would facilitate easier pulls, movement through the world and make common questing a lot more fun.
This is easily accomplished by adjusting the value of field npc_types.aggroradius and can be just as easily undone if you don't like the results.
I would suggest cutting the existing value in half or any other figure you think would be fair but balanced.
Thanks for your consideration ... Varnus