As for the rest, I agree with the general consensus that seems to be forming here. As worship leaders, part of our job is to keep everything running smoothly and as distraction free as possible, but when things do go wrong, we owe it to God and to our congregations to keep going and not get derailed. I think about the other thread that's going right now about setting a good example for the congregation in worship - it's the same idea. We need to model for the rest of the church that we can continue to worship (and worship passionately, at that!) when everything doesn't go as planned.