#1: The AI don't seem to notice weapons that you haven't given to them, and in order for the AI to notice them, it has to be outside of, and then enter their 'detection radius'. (So take the weapon off the table, turn around with it and give it back to them)
#2: Sometimes an AI will get stuck, preventing further AI spawns. Usually closing your shop (clicking on the door sign) will reset their pathfinding and let them leave, but if that fails you can walk up to them and push them around.