I have seen in the Unshaded that i can use multiple texcoords somehow, could anyone bring a bit light into how to do something similar for a own material?
Or does jmonkey actually does already read multiple texturecoords if aviable (ogre xml)? and I just have to access them in the material?
Yes it does, you just have to define an input attribute called vec2 inTexCoord2 in your vert shader and it will be filled with the coord if there are available in the mesh data.
Ah nice 
Need that secondary texture unit to allow the use of textureatlas + repeating textures