Derek, this is probably my favorite of what you've done so far. I have to say I really enjoyed the Boogie Woogie part (about 11 minutes into it). I also for some reason liked how you held the bass note after your romantic improvisation for a very long time. It gave me time to relax and think about what had just happened, I guess. The last melody in your romantic part was very beautiful as well, it seemed tinged with melancholy.
My only criticism is that is seems as though you rely on moving flowing lines too much (like arpeggios, and flowing, wandering melodies). This is something I do also. You might try doing something completely different - for example, take the Rachmaninoff prelude in G minor op. 23 no. 5. The first and last sections have very little "flowing" quality, more of a spiky, jumpy march with staccato and such. In contast, the middle section does have this flowing quality. This is a good thing to do, to have contast - something as simple as 'non-flowing', 'flowing', 'non-flowing'. I just had a thought. You could try putting some of the "Boogie Woogie" figurations and articulations the context of a romanticized, classical improvisation. Might be interesting!