What I would look from the trap mechanics would be:
1. Making traps
Based on the use of skills (mechanisms, craft, lore) and descriptions one could make a trap of different quality: how difficult it is to notice, how difficult it is to evade, how difficult it is to disarm, how efficient will be the effect (damage, attack roll, etc).
2. Mechanic of the trap itself
Like I mentioned, one could be able to: notice trap, evade trap, disarm trap, suffer by trap.
Based on that, I would think the qualities of the trap could be skill values for opposed rolls. The levels could be broad like for general skills: Novice, Apprentice, Veteran, Expert, Master.
So from top of my head, a trap would have the following properties:
Property | Creating skill | Avoiding skill
Stealth | Craft | Perception
Trigger | Mechanism | Evade or when discovered Mechanism for disarming it
Effect | Craft | Armor/HP
Success of applicable lore skill or good description will give bonus for crafting. And the trap's property value is based on the highest success level: Novice, Apprentice, Veteran, Expert, Master.
Just a thought. May be too complex for OQ?