This is a lovely review and the back story is absolutely wonderful. However, I think you made a few little mistakes.
First, the recording sessions leaked in 2010 and I think it's safe to assume everyone here has those. Wouldn't it be more sensible to refer to its track names rather than the track names of a randomly chosen bootleg?
Second, you state that the OST contains all the highlights. I beg to differ. For me, Nimbus 2000, Christmas Music Box, The Blue Forest, Hagrid's Flashback and Mail Delivery are definitely highlights.
And finally, you should definitely mention the Children's Suite.