Fantasie-Impromptu has, as you can probably tell, a lot of fast, running passage-work. It lies fairly comfortably under the hand but ideally I think you should have experience of having mastered some easier pieces with quick sixteenth notes or similar before you tackle it. The repertoire you have listed is mostly slow to moderato-tempo pieces. Have you played any small Czerny or Burgmuller studies in quicker tempi? Or perhaps som Mozart or Clementi sonatas?