So it worked when connected to a standard projector without any problems immediately.
Interestingly, the MBP has automatically and immediately converted to the resolution of the projector, in other words: there were two black bars left and right of the work area to see, since the projector no Wide XGA or has something. That is all that can be seen on the laptop, was also to see properly on the projector.
Sound transmission is (of course?) Does not take, and I do not know here whether the Thunderbolt ever supported or if the projector being used supports this.
For an image transfer therefore recommended seemingly unlimited.
If there are any changes should result in further use, I would report here.