I don't know about Soldier of Fortune 2, but in Quake III there is a fence texture (It's in
Base - Walls I think). You make a brush, put the fence texture on one side, and put a
No Draw texture on the remaining five sides
Triggered doors aren't really that hard (again, my knowledge is limited to Quake III), and I believe there is a tutorial on one of those websites I posted earlier in the thread, though they're aimed at Quake III mapping so I don't know how helpful they'll be.
As for destroying items, I have no idea... I know there's a way to make things explode in Quake III (I've seen several barrels do it).