i have succesfully rolled them without damage on carpet, then thin carpet, then on the table top!
they are not supr fragile, but they make one heck of a racket across a hard surface
the side that would have a 1 has a hole. this is from the molding process, and can be seen on the bottom of any decorative cast item. i have taught my mold guy how to make them without the hole and he is working on mastering the technique.
i am unsure as to how random they are, but after a couple of dozen rolls i didn't see any obvious leanings. this is about as unscientific as it gets