"hadn't of been" is another example of dodgy grammar. The 'of' should be 'have', except that I don't think 'have' is needed there either.
I notice that you can't spell quidditch - I can't spell it myself either, so I always check when using it. ;-)
As for the story, in a way I think you may have been better not splitting up into two threads but leaving Hogwarts alone until (unless) Draco returns. We'll have to see how it goes I suppose.
"The ghost" appears to be both Malfoy and muggle-born - presumably that paradox will be cleared up later?
One final point - when you switch viewpoints it often takes a fair while before we know _whose_ viewpoint it is. I suggest adding a note when switching like ...
* Hermione, Hogwarts Express *