Probably a little late, but I did a game once where I tried not to kill anything unless it was absolutely necessary to complete the game and I managed to get through Varn (for the most part) doing that - and I was probably considerably lower level than you were. In Varn you have to kill the Sentinel to get one of the keys and then I found out that I couldn't get down the stairs in the water temple without killing the critters in front of me (just couldn't get past them). Other than that I didn't kill anything.
One part of my strategy was to get somewhere, set a Lloyd's Beacon, Town Portal out, heal up, and then jump back to the beacon. That let me get past a lot of the enemies.