Thanks for the effort into making this skin, a notes so far:
Statik Seekbar isn't available.
Pro Buttons aren't available.
"Adaptive icon" what is this?
Can you enable coloring the text? Maybe to match the accent color. It would look good if the seekbar matched that color as well.
Also, please add different colors besides black for the background color.
And lastly, it would be cool if you could theme the Poweramp Icon and stylize the player PLAY button to look like the icon shown here: