Respect for making the effort to learn cad and getting into laser cutting. There is something to be said for leaning from those who have gone before you. There are literally 16,000 sets of plans on outerzone.co.uk. I'm not saying that you should slavishly copy things but you can observe common techniques. For instance dealing with the leading edge fill. The usual practice is to inset the perimeter of the rib by a distance equal to the sheeting you are using. This will allow you to extend the sheeting across ribs rather than filling in between them. The advantage is that it allows the sheeting to become a stressed portion of the wing and provides what is commonly known as a "D" tube that gives wing or control surface a lot more rigidity. Usually there is a rigid leading and trailing edge that is even with the front and rear of the flying surface ribs. That will prevent a lot of the covering sag. You might also want to check the rotation of your servos. I get the idea of doubling servos but you might want to check the rotation. In particular it looks like the aileron servos will conflict with one another.