I loved everything in this post, Luka.
Your interpretation completely makes sense. And it makes me very, very excited for the 50th anniversary. Although I still haven't seen the old era, I've always wanted to know more about the Time War. Ninth was brilliantly written and performed, and made me ask myself what hell the Doctor was just getting out of. We got some answers in series 3 and 4, but not all of them.
And, holy hell. John Hurt.
As for the episode, I loved it. I agree it wasn't the most spectacular season ending, but everything was done properly. Even River Song was great in this, despite the fact that I didn't care much for her arc in series 6. She only came back as the Doctor's wife, bringing back her death in Silence in the Library/Forest of the Dead in a very appropriate way.
Clara's arc and its unfolding is a bit underwhelming, but I think, as Luka said, it was more of a setup to introduce what's coming next. She remains a great companion to the Doctor, and I look forward to seeing more of her in series 8 (although I have no idea how this will turn out).