Little disappointed in Harry for giving up on Daphne so easily. Not to say that his attitude is out of character for him, just that he should realize that it seems out of character for her (especially after her good-bye comment). I would guess that her father had something to do with the 'dear john' note.
On thing this does do is give Harry a chance to date a round a little so he has some more experience. Only problem I see is that I would think he might be a little gun shy and may need some time to get over this. If he doesn't end up back together with her quickly (because it was all Dad's doing), I would suggest using Neville and Hannah to push him to go out. This might also be a time for Hermione to repay the favor he did by busting into the head girl's room.
Otherwise it is well written, as usual, and I like the changes you have made since the drafted sections were circulated on Caer Azkaban.
Author's response
- Everyone seems to expect Harry to have stormed the Greengrass Castle with wand blazing.
- Think about Harry's life, he's gotten the sticky end of the stick, in this timeline for the last seven months, he's had a run of abnormally good luck. From Harry's POV, Daphne just wised up.