Great news. Thanks for that. I disabled "only origins". But when i tried to fix the double assignment of bone movement, i didn't find a envelope/weight switch but the one in the armature modifier of the mesh

( i also turned down all values in the settings of the first big bones in the chain that are related to envelope, since there were values that i never entered there. I promise ;) ),

but surprisingly i now have several dozends of bones, but only a few vertex groups.

When i parented the mesh with automatic weights, there were much more. So, is this a bug that's derived from using the skin modifier or a severe blackout of my consciousness (maybe i fell onto my keyboard in a very unlikely way?) Either way there is still not much solved. I will test the skin modifier generated armature as soon as i can to understand what went wrong.

Oh, my bad then. I just removed all the vertex groups and the mesh still moved when I posed the bones, so I assumed it was envelopes.

i found out that i still had the vertex group filtering on (but hidden since last blendfile closure), so only groups with f were shown. I'm very sorry for having stolen your time. I deleted all groups, the armature modifier and the parenting, and then re-parented with automatic weights, and apart from a not so great binding of the head and some of the eyes, the mesh now behaves more or less as expected. Only minor weight painting is now to be done. Many thanks for the push in the right direction, and thanks also in general for helping making Blender so awesome!