Your interpretation seems pretty close to the one I had when I saw the episode. I was also concerned about some last minute rift between Spike and Buffy and I really thought it was passed off too quickly. Had we gotten the two hour finale we needed (or had less time been wasted during the season) I think this tension could have been dragged out longer in a more natural manner. I rather liked seeing Angel's appearance and the way it wrapped up their part of the show. To some degree things were left open. I got the impression she would always have a soft spot for him but that they had very separate lives at this point and in no way would they recross in the near future.