I don't see how you can say definitively DO NOT REMOVE BEFORE or AVOID AT ALL COSTS when you have a five man bullpen.
If you've got a LHP set to avoid RH and a RHP set to avoid LH and your setup guy just got "tired", and your mopup guy has pitched three games straight, you're gonna burn through a five-man pen pretty quickly. That's why I feel that they have to be viewed as your preferences, not absolutes
That said, I agree with nev, if I have a big $$ reliever, I want him pitching, not coming out before he's tired. But, let's face it, the best bullpen management is a complete game by your starter.