The first: I can not really comment on this image, it's a classic character with a spot on it. That being said, the hair looks poorly positioned on the skull (too much inside?) But I may be wrong.
In any case, no render will be good if you content yourself with a spot on your character.
The second: We are already getting closer to something interesting this being there is still a problem of light, always a spot (or distant light etc. ..) while it is necessary to succeed in a certain way to enlighten every part of the body to have a correct rendering. I invite you to learn about the methods of lighting in photography (3 spots or 4 spots etc ...)
You seem to be afraid of collisions, the right hand should be stuck to the thigh I think.
Third: Always the same problem of light so I will not come back on it ...
Apart from that I have not too much to say, it's basic with some concerns about clothes and potentially surfaces (difficult to say given the lighting) but it's really far from being the priority.