You want to fly an airliner upside down, sure here it is:
http://www.aviationpics.de/airshow/707buzz3.jpg
It is entirely possible and has been done.
Here is the corresponding video:
http://www.aviationexplorer.com/707_roll_video.htm
If done properly, the forces are not a problem, nothing would be ripped off.
It's called a chandelle and it's a 1g manuver. If your airplane is going to fall appart at 1g, you have bigger problems.
