Quote: "fpsc vanilla has nothing to trigger a specific animation when limb x is hit, even with the new limb-detection-system."
The condition your looking for is:
shotdamagetype= followed by any action you choose.
The numbers 1-6 corresponding to limb hit.
What your trying to do here is impossible with limbs flying off, for the simple reason that you cant attach and spawn a body part to fly off the character, this is the reason any mod will at best hide the part of a mesh which is to be removed (such as the head).
You could animate a detached limb but if you dont end any further character movement (i.e. kill the character) then they are just gonna have to drag that severed limb around with them.
If you animate the character rig you have the added problem of where it takes place, if the character is next to a wall or object then the limb could easily disappear inside of this, not a great illusion at all, without the limb having its own collision detection.
The only way I see this working is to animation to blow off the limb and in the final frame hide the mesh part inside the body, you wont have parts lying around.