How I’d redesign piano sheet music
What happens if you rotate that first image 90° counter-clockwise? http://i.imgur.com/i2V57On.png
You get a traditional sheet music with simpler graphics.What about the new features?  - Easily printable: traditional scores already are
  - Screen and scroll-friendly: you can stack traditional score pages vertically
  - Chord names: already exist on traditional scores
  - Lyrics: same thing
  - Foot pedal arrows: same thing

The only novelty here is to match a piano's physical horizontal pitch range, which forces the time axis to be vertical instead.I guess sheet music is like code: sometimes you just need to learn it the hard way.