I agree, the Underdark is beautiful. If not for that pescy bulette, it would be perfect.
There is a bug with the ball throwing? I never encountered any problems.
Yes, the bulette and the minotaurs were my only complaint.
The first couple times I got the ball from the dog in the dialogue, it either disappeared or I couldn't throw it. Very odd. I'm not sure what was different between those times and the most recent time when it worked.