Thanks for your kind and instructive comments, rachfan and perfect_pitch (do you really have it? I hear it can cause trouble when playing poorly-tuned pianos).
Re the tempo changes: Chopin, of course, marked stretto and ritardando here and there in the A sections. I tried to keep these subtle, but, in the end, of course, it's a matter of taste. The piece came right after playing a Beethoven sonata, and I fear my adrenalin was still flowing a bit much for such a lyric work. But thanks for your thoughts, subtlety re rubato is almost always better.