The key to any reinforcement is to keep it light. As previously mentioned, the tail is the worst place for added weight because of how much is needed up front to balance what was added in the tail. Build the plane to survive flight loads and not much more and it will fly much better. I’ve seen planes that were “improved” to the point they were flying garbage trucks.

On the sharp trailing edge, I’m not sure that is a good idea. There is some evidence that points to thick trailing edges (TEs) being better than thin TEs in that the plane tracks better (less wandering around the trim point.)

As to the material, I’ve never used specifically G-10, but I’ve used phenolics before in planes for structure. The main downside is phenolics are very heavy, so application has been limited to servo mounting plates, breakaway LG plates, nose rings, etc. where the part is small and very high strength is needed, i.e. I use it as a cheap replacement for carbon plate on planes that don’t deserve the carbon.