Well, I'll shill for my theory some more. Here it is again:
1) Those are not actually Morghur and beastmen, those are dwarfs of Karag Dum.
2) They changed their bodies using the knowledge gained from living at the edge of the Wastes.
3) They did so because when the Wastes expanded, usual protection ritual failed, and they needed better bodies to either live here at all or to fight outside of the protection of the stone/runes.
4) "Morghur" is actually an important member of a Royal Clan/Runemaster that is either related to or knows Borek very closely, which is why he used a very intimate gesture.
5) Borek knew that such plan was possible, which is why he was not surprised, but he finds it horrible for obvious reasons, and thus orders us home.
I think this theory explains what's going on, the actions of both Borek and "Morghur" and why Karag Dum still supplies pure energy down the waystone. I am opened to critique, and if you are convinced, please vote this.
[X] THEORY: Neither Morghur nor beastmen are what they appear to be - they are instead dwarfs of Karag Dum, who changed bodies through principles they knew but still kept their souls and minds intact. The reason for that was the need for new bodies that could survive fighting in the Wastes. "Morghur" is a member of the Royal Clan or a Runemaster that knew Borek personally, which why he made such an intimate gesture. It is possible that not all dwarfs suffered such fate, if that is the fate they suffered. Borek knew of such plan, but found it shameful and thus fell into despair when he saw it done.
For action, though, I think a more simple vote is needed, something that all who wants to stay can agree on. Let's say, this:
[X] ACTION: Expedition: Digs in; Mathilde: Investigates
[X] ACTION: Attempt to contact the nearby Kurgan tribes for information.
[X] ACTION: Attempt closer examination of Morghur, the beastmen, and the forest.
[X] ACTION: Infiltrate Karag Dum to gather information.
I think whatever theory we choose, first thing Mathilde will need to do afterwards is investigate one thing or another - forest, other tribes, "Morghur", "Beastmen", whatever. Does anyone who wants to stay and find out what is going on disagrees?
Edit: Included a few more general options. Please approval vote whichever you like, if you want to stay.