Unfinished Sketch - having trouble

I need input on the above drawing. I traced him from my sketchbook, where he was part of a larger drawing with multiple figures. Here the figure is isolated on a sheet of tracing paper and partially penned. The lower half of the body is a problem for me -- I've blocked it out to get the forms, but I am not satisfied. In the end the figure will be wearing tight corderoy pants, a T-Shirt and some sort of loafer for shoes. He holds in his right hand a microphone that I've only loosely sketched in.

How can I improve this? I'm not confident in my use of anatomy. I particularly mean the yet un-penned part, but constructive input for any aspect of the drawing is appreciated.

P.S. The figure is supposed to be Blind Melon's singer Shannon Hoon, of whom I've previously posted a sketch. Unlike the last sketch which was from a photo, this was drawn from imagination. The drawing is intended to take after the music video for the song No Rain, and I want the finished piece to have the iconic Blind Melon butterfly girl and ideally the other band members.

From my sketchbook

This is a page from a recent sketchbook. All the line work is done in col-erase pencils. Pictured on the top left and right are drawings of the first cosmonaut. When I look at this drawing, I can't help but hear in my head "... this is ground control to Major Tom, you've really made the grade...". Lyrics from one of the two Bowie songs on my playlist. I never want to travel into space -- that kinda thing scares me more than man-eating sharks.

Fight Scene

This is a drawing that has undergone as much GIMP work as I could tolerate. It was a two page spread in a sketchbook I fondly referred to as the big'un. I stopped using that sketchbook because it was way to big for my puny-ass scanner. I had to tile this together from four separate quadrants. I then selected the line-art, converted it to a path, then had the path traced with a calligraphic Gimp brush. I like how it turned out -- I'll post the line drawing for comparison.

I love dogs

I drew these from photos I found on google image search. Dogs seem so expressive to me, I tried to capture each dogs expression and exaggerate it. It's hard to believe that domesticated dogs collectively are a single species. There is so much variety among them.