Containers

Don't forget that containers (chests, dressers, long dead corpses to loot, etc.) should have the following flag set under the behavior section of the properties window:

Has Inventory?: TRUE
Static: FALSE
Useable?: TRUE

If you want dynamic treasure, make sure you define a treasure script for the On Death and On Open events. One option, gp_treasure_op_de, is documented here: http://www.wendersnaven.com/node/65

Leaving the faction to hostile will allow players to bash the object without any real repercussions. In NWN1, setting the faction to a neutral faction would cause any nearby members of that faction to attack the PC if certain events were triggered. If I recall, these were On Death and On Disturbed. I'm unsure what events trigger reactions in NWN2, but they are probably the same.

Converting to Environmental

Converting placeables to environmental objects reduces the size of areas. I think it also increases performance for players. Environmental objects do not cut into the walkmesh, meaning that players will be able to walk right through them. Sometimes this is not an issue, such as when they are out of the walkmesh anyway, but otherwise you will want to use the walkmesh cutter trigger to keep players from walking through your objects.