A nice idea (to put the "environment" into game strategy) is placing some explosive items on the map. If player targets them with ranged weapon (or melee if going for the suicide :D) they explode and heavily damage nearby actors (e.g. like 5 pts of damage).
Might also be sometimes "masked" for normal items (thou still visually different), fist of all - vases, but also any other items like coffins, chandeliers, cages (not real, a trap).
The same way some tiles may cause cave-ins (dropping stones around and damaging nearby creatures including player if unlucky (or rather unattentive, as they're a bit different in look)).
I love this idea. Explosive barrels could be implemented the same way like vases. Cave-ins maybe could be caused by traped doors?