(Dang, I accidentally closed the tab and lost everything I had just written.)
First, I thought that both performances were lovely. I have always adored that Mazurka for Chopin's writing that "wrong" note at the end of the main theme.
Your performance of the Impromptu does it justice. You do a beautiful job of conveying that swirling, twirling, waltz-like outer sections.
The middle section I believe would do better with a more relaxed, less insistent tempo. The marking is "sostenuto" in each of the editions on IMSLP (unfortunately I don't have an urtext or even the Paderewski ed. available). Here is what the Dolmetsch dictionary has to say about "sostenuto": (1.)(Italian) used alone as an tempo indicator, sostenuto means the same as andante cantabile" (4.) "(a passage) played in a cantabile style". It is thus a tempo indication. In fact it is placed in the "tempo" position above the system in all but one edition on IMSLP (granted all four could represent variations on the same source.) Also, if you compare it with no. 3, which also begins with a perpetuo moto triplet section, its middle section is also a more lyrical section marked "Sostenuto". In the posthumous Fantasy-Impromptu, the "I'm Always Chasing Rainbows" section is marked "Moderato Cantibile."
Anyway, a more relaxed tempo will allow you to play those detached bass notes (I think that he is somewhat thinking of the light sound of pizzacato bass viols and not necessarily "marcato") with greater ease and less fuss.
One other thing, each edition marked the passage between the turn that begins with the 3 Bb's and the longer sixteenth note fioratura with a rit. or ritenuto. I would like to hear more relaxation in the tempo which I believe would give even greater impact to the fioratura.
Over all, a job well done -- particularly late at night.
Scott