You asked for them
pause-overlay.png - should probably be a jpg @ 95-99 quality. Crop to 1024x768. 1.4 MB is kind of ridiculous.
More combobursts.
comma, dot, %, X all look like they were made differently--they sort of have a blurred outline rather than the sharp one that 0-9 do.
fail-background.png - should probably be a jpg @ 95-99 quality. A vector/original drawing would be nicer than a screencap.
The template skin has 50 smaller than 100, and 100 smaller than 300. Something to think about. You've actually got 100 > 300 by a small amount.
reversearrow.png - the shadow is red??
playfield.png - could save as grayscale to save on space.
spinnerbackground.png - ^, also it's kind of bland since the alpha transparency just defaults to black.
scorebar-bg.png - why is this transparent?
in skin.ini:
//Score fonts can be drawn differently to hitcircles. If you only want to use one font, you can set this to the same prefix as your hitcircle font.
ScorePrefix: default
so you don't need two of every number.