1. Not as is, but some one made an addition to FPSC to get this in it at runtime also.
2. No, but there's a work around. You could create a script (I've done it for my own game), which allows you to use a secret code to open a door. FPSC does not have any keyboard input like that.
3. Yes, totally possible, but limited. You cannot create huge worlds, with lot's of foliage, that will bring the engine to it's knees. But you can create convincing outdoor levels. Follow the link in my signature. Then select Media & Games on my website. Select FPSC Landscape Pack 1 on that page and there you can download a demo and see screenshots of landscapes in FPSC.
4. I'm not 100% sure, I've heard people mention it, but never seen it.
5. Dynamic lights yes, moving lights I'm not sure about it. BUT.... the engine cannot really handle dynamic lights too well. Even though it's an implemented feature it really kills the game.
6. Not sure, I'm at my laptop at the moment, so I can't check.
7. Yes, but you have to create in yourself. Someone has done it already, it didn't sound too complicated. You can also simulate walking through water.
8. Dynamic Fog is possible, but you cannot alter the range of it, unfortunally. Fire is possible through decals, which you could also use for Fog.