I will definetely mention you have improved.

Scrolling down I thought it looked quite professional, I like the detail and minute brush strokes used around the face and head area. It would have been nice to see the same brushwork for the lower half. I know it might be a bit hard, or you might be tight on time, but giving it patience will make the picture more worthwhile in the end.

The shorts need to be fixed up the edges look a little rough. The lighting and shading of the guitar looks a little flat compared to the rest, so it would be nice to see it spruced up. I personally don't think the hands are too bad, the reason you feel they are off is because there's no shadow under the arm for the guitar. You've used a seperate light source. I will only say the right hand looks a little big on my part.
Other than that, I'm really enjoying the picture!XD Good work Yuzero.