3. About Sion, in the normal game he does not start hostile & Ariena triggers the teleport by the way, not a fight. So I wonder if it is an incompatiblity with Improved Guarded Compound. Perhaps you need to de-install that and see what happens, if it still going wrong then it is Ariena herself
I don't have improved compound, and she does the same thing. It seems like the other person who's with him dimension doors, then it says (and shows graphically) that Ariena dimension doors, but she stays right where she is. And Sion stays and remains hostile. A Sion character shows up upstairs and is killable, but when you come back down, he's still there and invinceable (haven't tried Time Stop/Shapeshift: Mindflayer, but I have a feeling that won't work).