Actually I have done stuff like this in a few things, a few different ways.
The NewBirds use a MantaCarcass for their gibs. I just have the pawn class spawning a MantaCarcass and gibbing it right in the code for
Used a different method in the Zombies5 things. The zombies use several different monster gib classes, but the
assignment is made in the defaults for the individual zombie pawn classes.
Green gibs for aliens is easy. Just use a Mercenary or Slith carcass.
Metallic gibs would be a bit trickier. Would either have to find some existing classes that could be tweaked into robotic gibs, or
create a new carcass class one way or another.
Slippery blood would be a whole other topic entirely. Not sure how one would go about changing properties on the blood decals to simulate a slippery floor.
That would require some testing and research or something...
Would be somewhat hesitant to dive into this project at the moment, as somebody else is already working on a new gib/gore system for UT
that is looking very interesting from the previews. Waffnuffly over at UnrealSP.org is doing it, and has posted some killer preview videos in the
thread for his EXU2- Batshit Insane project. Details and the vids in this giant thread: http://www.unrealsp.org/forums/viewtopic.php?f=4&t=1651
Kickable gibs, a bunch of new blood colors. All kinds of interesting stuff being worked on there.