1) Can you make the shape of the >>| button look more like #15? See my notes in the general notes section.
2) Can you experiment with the O's? I like the general shape of the O's in #11, but see if you can come up with something more like this: http://i.imgur.com/es0AiiY.jpg?1
3) Can you experiment with filling in the buttons with a different color? It may not look good at all... but accenting the playback button with a little bit of color is an idea that may help, not sure... Try Red, Blue or Purple. http://i.imgur.com/kYf8Ub4.png?1