I agree with the cables needing to be a straight shot. No need to run them through tubes. I would remove the tubes and enlarge the holes in the formers so a straight shot is possible. Two other things I notice, it appears that you elevator control horns are metal? If so just looping the cables through them is not going to last very long. Secondly, your servo arm is way too long and is contributing to the play you currently have. Lastly is the steel cables themselves. I stopped using steel cables years ago. They stretch, are heavy and although unusual can pick up and emit RF. Instead I use nylon coated Kevlar cord. It will not stretch and is much lighter. The install is pretty much the same, use a K&S aluminum tube, crimp and add a drop of CA.