Great composition. My eye is really drawn to his eye, which looks really cool because of the massive amount of contrast there. I'd be interested to see how this looks with the brightness and contrast boosted a little.
Know what you mean about the over-sharpening, but it's pretty much a judgement call and I would have said this is a sharp enough shot to take it. V. good. :)
I don't think you oversharpened this, it's looking good. There's a bit of noise in the background, probably from the sharpening, but it's definitely minimal. I like the similar color of the background to the ferret, and how the pink stands out. Very nice!