Thanks! Flash seems terrible for frame-by-frame animation; It's so hard to reorder frames and things and could really use a lot more keyboard shortcuts and less confusing frame-dragging behavior to speed up the process. I've tried Toon Boom Animate Pro before in one sitting, it was barely enough to get acquainted with how to use it but it seemed kinda okay.
Anyway, great job on this horse run. And your other horses too!
True, Flash is bad at keyframe organization. Toon Boom Animate Pro or Harmony are much better at it, since they have an X-sheet window. I recommend putting in the time to get to know Animate Pro (or Harmony). I personally love it because it has an X-sheet, it's easy to color the frames, and it has shift-and-trace capabilities, among other awesome details