I've just started playing arma 2 so I don't know everything that is out there. However I have watched hours of game play on Utube and didn't see the following:
Sabotage/traps
1. Rig a vehicle to explode after ignition.
2. rig a corpse to explode if searched/moved.
3. rig a door to explode after opening or turning the door.
4. rig a mechanism to explode after an object is picked up
5. pit traps
6. animal snares/ can be used on people
Trip wire.
1. Trip wire to sound alarm
2. trip wire to detonate something like a tripwire mine.
3. laser wire to activate a silent/loud alarm.
Wild animals react to players/npcs.
1. Birds get scared and fly away after hearing gunshots/noises near by. Can be viewed from distance.
Same for other animals.
mines. I hope there already not many of them on the field.
-whole assortment of mines.
weapon jams, weapon degradation/maintenance, weapon melee.