I'm a planner, too! I totally loved knowing when I was going to go into the hospital and have my baby.
Yes, I asked for a mirror, and it was totally motivating. I pushed a couple of times, and could actually see his head crowning. It really helps with pushing, because you can actually SEE what's going on down there. I had to tell the nurse a couple of times "move it to the left! no, a little bit to the right...little more...little more. THERE! STOP!"
But, if you end of having to have an episiotomy, I'd suggest having them move it. It's like a car wreck - you don't want to look, but you just can't help it. And that's something that I could have lived without seeing!