1. i am in the serpent temple and i cant find the inquisitor. i am in the area of H,Thark and i went into the room with the brazier but no inquisitor.

2. i jump into the serpent pit and kill the unholy slime thing but i cant get further in the tunnel to get the chest. its like im stuck. my party drowns even when im not really in water. but mainly i cant get up further in the tunnel

I forget the answer to the first problem, Ironworks Forum has a lot of discussion of various W&W quirks and errors. Also, it has at least one walkthrough.
The infamous problem with avoiding drowning, I used Vanish as I recall.

i did the twirling thing with my head down and that worked.
but i still cant find the inquisitor. what if i beat him earlier didnt know it and didnt take the key

I found this on Ironworks Gamiing Forum by a user named Sloth:
"The Serpent Inquisitor will be called that. If you are attacking a torturer, then that is not him. The easiest way to find him is from the large snake head room where you will summon the Naga. Look behind you, and use the snake head levers. Facing the Snake Head, go to the left. Keep hugging the left wall, and he is directly behing one of the doors. If you think you already killed him, then you will have to "pixel hunt" for the key in the torture chamber. What that means is you will have to scan the floor with your curor waiting for it to change to "?Strange Key?". If you are in a real bind, you actually do not even need to get it. There are some posts on here that will tell you what the prisoner (H'Thark) says."