So I rescued Rugan and Olly from the Knolls and convinced them to let me have the chest with the persuasion check. I then went to the Zhentarim Hideout and I am "welcomed" by Zarys. Thing is, she is standing in a no-go zone. So if I approach her and talk to her, everyone immediately attacks.
I can get around this, but it is hacky. Basically, have to send someone up who has invisibility on and then push her off the ledge down towards the merchant. (This only works because of an invisibility bug where you can push and not break invisibility) There, I have another (unchained) party member waiting who talks to her while she is in the safe zone. This allows me to get paid and report on the chest which updates the quest. But I have to use the invisibility cheat to talk to her.
Obviously the dialogue is there to pay me for rescuing Ruban and to turn in the chest if I want. So it seems to me she needs to be placed in a different spot or you need to redefine your no-go zones.
Yep, same issue, she say we can access their special stock but the trader keeps saying she needs to say so first and only has normal items.
Another possible bug is the elevator/lift to the Underdark at the back of the cave. You can steal the key from off of the Zhent NPC's however the entrance to the elevator is just covered by a cliff face. I only found it because you can walk right through the cliff. I don't recall if there was a perception check, but it's didn't come up as being a hidden door or anything. Possibly it's just unfinished at this point.
The loot in the locked rooms is also kind of pitiful. A few gold coins and such.