Investigate Kagha quest is bugged

[dafdefet]

I returned to the grove with the letter and triggered the fight but there are a few issues:
1) There are NO rats in the room when I speak to her and so there are no shadow druids in the fight, which means I cant get loot from them (whatever they were supposed to drop)
2) The quest doesnt complete regardless of whether she lives or dies at the end
3) The servant marconius is already dead in the servants quarters - does this have anything to do with it?
4) I can attack Kagha after letting her live and nobody reacts. She doesn't event defend herself and can be killed and looted (completing the kill kagha quest). I can even attack and kill Rath the same way (and the two halflings.. this is nice for loot but makes no sense. The grove doesn't even aggro after this)