Coby Rendal helped me out on the wireframe / backfacing culling issue and theory. Though one last step for my base is left.
I want to have the back of the sphere slighly bleeding into the visible part. Like a fresnel effect on the transparency. With backfacing I assume a black and white map is given to the shader. Hence, fading it out is maybe not the easiest part.
But maybe someone has a cool idea on how to do smth. like this?