My opinion....and it's not an expert opinion by any means. I have sat in a courts marshal for similar charges and have witnessed the outcome. My guess is he won't get off with nothing but his sentence will be light.
This situation/case is incredibly politically charged. It has been since it was personally arranged by the POTUS for arguably political reasons. This will sway the outcome to some degree although his jury will be soldiers who likely have precharged notions of his guilt. Human nature....
He will get credit/leniency for 5 years of alleged torture, he will not serve a life term in prison, he will get a light smack with no back pay and dishonorably discharged.
That's my guess....That said, I'm not betting the family jewels on this outcome.
Also, my opinion, he's a nut job who should have never entered into any armed service. What he did is a horrible act, something that would be better understood if you've served in a combat environment. Yea, I know it's all heresay but at this point it's pretty obvious he didn't serve with honor and distinction. Even his lawyer is playing the AWOL vs. Deserter card now in an attempt to reduce punishment so he's certainly not going for the not guilty play.