Quote:

I don´t know much about shaders, but I´m going to buy the Commercial-Version and I have to know something: Is it possible to script a mirror-shader for the commercial-Version? It don´t have to work on Textures, but only on Entitys.



Not possible using A6 Comm & C-Script alone. In A6 Pro you can simply assign a camera view to an entity's texture.
Using a DLL it is possible to copy the framebuffer (=screen) into a texture. To my knowledge no such DLL for A6 is freely available at the moment.