Also...

Realtime manipulation is (as I expected) no option for
me, because it is as complex as I expected to sever meshes, create triangles and texture them.

Vmask... the parts of the models are just clipped visually?
This must have disadvantages... how would it work in detail specific for gamestudio?

(Reading manual regarding Vmask).....

You are Right. Vmask gives great possibilities. And I found
through that, that I can bones give names and can detect them via C_traces Hit structure through the vertex attached to the bone.

I have to experiment when I need it.