Re: Harshness problem! help!
Use a serrated knife. Think they are too hard for a straight blade (though I haven't tried, and could be dangerous if the straight blade were to slip since you are trying to cut a small item).
Anyway, how are you packing the bowl? I actually almost always use 3 CH coals and never have to drop it down to 2 because of harshness. I also always smoke outside with no windcover though.
Finally, I think starting off with 3 and dropping it to 2 would be good after 5 minutes or so. It also depends on the shisha. Some are more heat tolerant. Good luck!