Wim,
Please visit http://beagleboard.org/discuss. I've copied the mailing list here for your knowledge.
The physical dimensions are best pulled out of the design files at http://beagleboard.org/hardware/design.
Most of the information you are seeking can likely be found in the System Reference Manual at http://www.beagleboard.org/uploads/BBSRM_6.pdf.
Regards,
Jason