Wow gutsy work there Kat ... but you do have the right model for the job
I think I can see what's in your head and what you are trying to achieve.

I agree that the fireplace is a bit too much distraction. Something more uniform in texture or pattern would work better I think ... OR ... the fireplace might need to be stronger even if it's not centered in the shot.

In terms of should the body be brought out more ... hmmm ... if you are looking for a more sexual feel then absolutely ... and the 'man' in me says "Hell yeh!!" ... but to retain the mystery I think you got it about right.

Not sure about the two positions. Not sure if this needs two positions. Perhaps a set of 3 photos identical in terms of processing, composition, etc but you in a different position for each shot is the go. That way you would be doing 3 shots properly rather than comprising 2 positions in a single shot. Sort of a sexy 3 plaster ducks type I guess
I guess if the movement is an important element in your vision of this then perhaps not.

Lighting wise I think you need to decide on one or two sources. The fireplace here suggests another source of light but nothing else appears to reflect that light source.