These are great, I wish I had your talent. I love the expression on the guys face in the last picture especially.

Your proportions look good to me. The girl in the 3rd & 4th drawings shoulder looks a bit odd, but other than that I think your line art is very good. There is one thing that really bugs me though, the chain-mail texture in the second to last picture. It looks a bit out of place, and flat in my opinion.