I love how you didn't knock any of the corners off of these characters. Even Snape's disdain of Filch for wanting to beat the students was wonderfully IC.
I never thought of the anagram for Pince, either. Have you ever met youself coming around a corner?
Oh, and, Argus Filch wasn't certain what she meant with her talk of intimacy, but he knew he meant to find out - *ba-dum-bum*. Awesome.