Quote: "So just to clarify, all of the graphic packs are compatible with FPSC but only as static items?"
Yes.
I'm not sure if scripting will allow you to run any of the Darkmatter animations.
Quote: "Would it just be a case of dropping the graphics into the folder for entities? and selecting them in the editor."
No. (but close!)
You would drop in the .x file (3d model) and the .dds file (texture)
You would also have to create a little .fpe file for them using notepad. You could copy an existing .fpe and just edit it to point to the correct model and texture.
One more thing - the weapons that come with Darkmatter would not be "plug and play" for FPSC. You would need to do a lot of work to make them as actual weapons you could use in the game (see the manual for the tutorial on creating your own weapons)
I have Darkmatter 1 so in a day or two I will run some tests and see how the items look and feel in the game and if there's anything special that needs to be done (like rescaling them). I'll post the results and a screencap here for everybody.