I like where this is going. Let me add some thoughts:
a) Iron can be found in the Deep Forest.
b) It is a requirement for all of these, as they all need some iron
I'm not entirely sure where to fit the trap idea into everything. It should be more than just a fence with special rules. Maybe traps could only be placed at the edge of the village, and can only be damaged by the largest creatures?
A weapon could allow a peasant to patrol the village at night. He would try to stop and scare away creatures, but has a small risk of being eaten. Basic concept: The patrol would cover all plots of his family and their neighbour plots.
