On a re-read one thing occurred to me. You mention in one point that some of the ravenclaws turned completely into pigs.
How could pigs apologize since they cannot speak? For that matter how could they make restitution? Cannot exactly buy a box of chocolates when you are a pig afterall.
Author's response
That does make it tough, doesn't it? Whoever said redemption was easy? Oh yeah, Dumbledore did. BJH