To answer your question(s)
No, you cant just skip the AC and run a shorter belt due to how the belt routing is, and that EVERY 3800 was factory equipped with a AC compressor.
Most you can do is buy a "delete" which is just your standard remove the compressor, and install this ribbed plastic pulley instead. Weight savings yes, power gains...probably not.
As for the threads being left hand, yes. To remove the pulley for the accessory belt tensioner, left is tight, and right is loose. The one for the supercharger is your standard thread, right tight, left loose.
~F~
