Hi @Ohki, I'm glad that you can see the problem too, because I starting to think I'm overreacting.

I actually made several attempts to fix this.
The progress so far, I re-grouped the neck and head and changed the position of the neck and head bone.
The tricky part is to get the weight mapping right so that the head and neck geometry are working together.
So far, I got some strange looking results, but I like to try it until it works.
Maybe you can give me a hint on the weight mapping process I should use.
It has three options if I remember correctly; delete, add and replace.
I have not really that much of experience in that matter, so I just go by try and error.
Add seemed to me an obvious choice, because that way I can work with whatever the figure has and build upon it.
The problem that comes up now is, that the open mouth morph seems to influence part of the geometry that I re-grouped from head to neck.
That causes the throat to deform unexpectedly, the chin moves like a canopy, it's looking bizarre.   
But it's actually fun to work on LaFemme that way. Until to this point in time I only posed her and did pictures of her, this is now a completely different field of work.