1- rotating the image so that her body is coming out of one the lower corners might work better here. I agree with the above comment about wanting to twist my neck to see it. Why did you chose to shoot like this?
Seems that she was posing, so maybe trying to get more of her hair out of her face to draw attention to her face and eyes. I don't like the white vignette, it comes off as a cheesy effect. Also not a fan of the carpet.
2- I like the suble lighting in the photo, but the frame composition is off to me. I don't like how there is a top part with nothing and a bottom black bar with nothing. Maybe a slight tilt down of the camera and making the neck of the guitar a little less horizontal might add some motion.
I do like how you played with the depth of field, but the composition needs fixing
3- Um, no. Subject looks jammed against the lens, wait too close in. I feel bombarded by the image. The black and white treatment seems to be lacking some contrast, and the image itself seems to be lacking sharpness...was the bw conversion to mask some noise or something?