Hey Eric, great job on your armor so far and as you said, it`s a bit big on you... I recommend cuting the top of thighs, a little at a time...regarding the sniper knee you could try some foam back of thighs and front of shin (wait for that untill you trimmed the thighs to the right size if you choose to go that route) The kidney and backplate looks a bit big as well, I was lucky to have my armor fit me like a glove without any modifications so I highly recommend you to read this build to help you resize your armor, it´s alot to read but well worth it!
Now it`s a bit different since you got the ROTJ with the fused butt/kidney but I´m certain it will be helpful none the less
Good luck!