The lines on the leg are a result of alphaing out the top of the boot, and due to the amount of pixels that are available to work with the only way to remove those lines would be to make the skin size much larger, and therefore allow a smother alpha selection around that area. Or the model could be edited to have the top of the boot removed. That is as close as I could get for this skin though.
Also, like Apheraz Lucent said, the ear is two shades because it is two polygons that don't line up, so they get shaded like a piece of paper folded in two.