Thanks very much for your reply, Peacelover!
That is the exact kind of critique I am looking for so thanks a lot!
@1st pic: Very true, when I was sketching the 1st pic I had difficult determining how long the legs should be, and I think I ended up making the legs too short in proportion to the overall body so that's why he looks short. I was eyeballing the original picture so this is prob. why my proportions are out of wack.
I need to study more anatomy and general practice of drawing characters to get a feel of personal guidelines that I see other artists using (like the length of the middle finger should be the same length as the beginning of the wrist to the top of the palm...stuff like that!)
@2nd pic: I see now that the gun's orientation does not match up properly with the eyes. I think I need to work on my perspective, and I just recently learned about 1D, 2D, 3D, etc. perspectives. The gun is definitely twisted slightly at an angle such that his eye does not align properly.
I am actually very new to the world of manga drawing and started my first manga drawing ever at the beginning of this year so thanks very much for your encouragement...it means a lot!