Sooo, I finallly got around setting up my raspberry, nothing too special but maybe it helps some people.
The thing with the screen was rather easily resolved (if only I could have been able to see something :).
It involves pretty much tinkering and the trapezoid picture of the tube didn’t help.
In the end I added to the /boot/config.txt file to this:
The framebuffer_width/height are set back to normal.