We started making our own framework for over a year. Our game All Mighty RTS is built on that framework. Unless you're a OpenGL guru I wouldn't recommend going down that path
Use libGDX. I would estimate it would take us about 1/4 of the time to make All Mighty RTS over again in libGDX. The end product would have much better performance though
(we debate doing this)
You do have to put in some physics (at least for 3D), but collisions are set up for you.