PF,
I do understand what you are saying to some extent. Just please be confident in "your zone" (since we all know the book zone does not exist) and be consistent with it. NEVER change what you would call because of a pitchers reaction on the mound. As a coach I will let into my pitcher if I see him react on the mound, that is my job. If I do not do my job and he continues to react, let the catcher know, or go talk to him, or send him to the bench if need be. But, do not change the zone, that is unprofessional and I would talk to you about it between innings. Always remember this, it is innappropriate for the pitcher to publicly act disgusted with a mistake call, but, you have to remember that you publically reacted by making that mistake call that may affect his game. Stay consistent and let the coaches do their job of handling the pitchers. Like I said before, if they don't, then say something to the coach.