Oh snap Hey Snake
yes you can!
It all depends on how realistic u want it to look, and what methods you use, there is really only 3 ways of doing it, deco mesh, moves and a combo of both, as well as the emitters. i found when using a a system that only uses movers the performance remains the same regardless of how destroyed the map becomes, when using deco mesh the maps performance increase as the terrain becomes destroyed but the lack of rubal on the ground looks unrealistic. The best method is a combination of both for example a tile created out of 5 deco mesh pieces set to an invisible mover that falls to the ground on an event, the event being any of the 5 pieces being hit.
5 deco mesh set to event damage or destroy event Helper01
hard attached to a mover who's tag is Helper01
when one of the pieces is destroyed the rest fall off making for some nice rubal on the floor but keeping performance as high as it can be, by removing the impacted piece.
There are a few issues with a fully destroyable map though.
first ai bullets don't trigger the events, know idea why they just don't
second being the emitters, it looks great to have them but they do sap cpu power quiet heavily when cutting a pillar in half with a m249
the third issue is the time it takes to create a map such as this, basically you need to create 3 maps, the backbone, the non destroyable shell if you will. Then you need the internals, brickwork, structural reinforcements, wires pipes ect that are inside the walls. Finally the facade tiles, walls, all that good stuff. Its like making 3 maps in one, that alone pretty much forces these types of maps to be small in playable space but large in physical size.
The final issue is the lack of large projectors such as 203 impacts and rockets, this is ok until you have a destructible part over lap a bsp or static mesh object, no real issue just looks cheap.
The next step in my development of destroyable maps is to find key areas of impact, an example of this was on my first ever attempt at doing this, i created a destroyable front for the defense tower on bridge crossing, knowing that 60% of 203s shot at the tower hit the walls i set it up to blow holes in it leaving things such as the top of the tower, tunnel and all that good stuff non destroyable. This is the next logical step in destroyable maps, it should reduce there file size, and increase performance as the map becomes more destroyed while to the untrained eye remaining almost totally destroyable.
anyways i have a bunch of prototypes for this sort of thing ill gladly give you and anyone else whose interested in creating a similar system, though be for warned its a HELL OF A LOT OF WORK!
ps: almost forgot SFHoStractions now finished, maybe you feel like jumping in a uh60 black hawk as US Delta Force and giving it hell to some Chechnya rebels on this custom modification to sf extraction or maybe you would prefer to keep your feet on the ground and show these rebels what your made of as the elite Russian Speznes either way you can do it on SFHoStraction. Also it is currently available on the wcs training server if you don't want to play it alone we always have guys on who will come play with you.
Will send it over xfire or post the link once i get the fttp updated, i will also probably upload it here for you guys once i get some more screen shots, here is a few to wet your lips..
In the ss there is only 1 person in the helo it can carry 3-4 players without issue, and yes it does move lolz, even drops you off on the deli rooftop, if you later smoke the LZ it will come back and pick you up for a helo extraction.
but i would be glad to share them with other map makers as long as you promise not to remove the WCS insignia.
Destroyable terrain sounds really interesting... does it react as in craters and holes? and working toilets... sounds nice lol - glad to get rid of that smell 
nothing worse than a great map and a pants ss lol
