Flintlock1415
Emperor
Well, I don't know, but I even tried just importing and then exporting the leaderhead without changes, and I still get problems. I don't get it. 

Basically you could try to group the item(s) and the main body. There are also menus for boolean operations like AND. But I bet this will screw up the skin partition. You would then have to rerig (I think that's what it is called when you assign weights to the vertices) the mesh which would be a big work. I always keep the parts seperated...When I import side objects (like items) how do I attach them to the main body in 3ds max so they are exported as a single branch for nifskope rather than 2 separated objects?
I never tried that by my own and never heard that anyone else did - on the other side I am not that deep in matter and it wasn't necessary to discuss that with anyone, so Ekmek & Co. could have done this without my knowledge - but theoretically... It seems like Nifskope doesn't provide the option to add a SkinInstance, but you could copy it from another one. In the meshs main node you could then refer to the copied SkinInstance node. Then you would have to alter that new node. I've seen that there is a member that stores the count of the vertices the mesh has. You will also find a bone list which are used for the animation and a member storing the count of the bones controlled by the skin. Also there seems to be nodes for the vertex weights storing the vertices ids and their weights. The vertices aren't shown in the 3d view (I never recognized an option to enable that), so you would have to find out neraly all data via Blender or 3dsmax (vertex id, count etc.). Finally there is a risk that the ids got corrupted when exporting (in other words the vertex id you want to set the weights of can be different in Nifskope and 3dsmax / Blender) and of course that would mean great work with few comfort. And there is still data I don't know what it is for...Is it possible to assign some children "value" just from the nifskope without external rigging/animation? If it's possible, please explain . I'd be very grateful.
Ok, so I managed to finish the leaderhead, but when I open Civipedia, it's a mangled, animated mess as you can see in the first attached picture.
I've seen quite a few people with similar problems, but I have no idea how to solve it. I'm sure it has something to do with the shader that you see in Nifskope (I don't know how to explain it, see the second screenshot attached). Without the shader turned on, nothing shows up apart from the eyeshadow, the teeth and the tongue. With the shader turned on, it shows up but is a mangled mess.
I'm making a shader version of the leaderhead, by the way.