Re: Forcefield to full power save the floor!
although i'm interested to see if anyone comes up with something more novel, I have to say I would just get a small area rug that could be rolled up and stored. doesn't have to be huge. Also, not using round coals would help your potential rolling problem. If you must use quicklights, you can break them in half and then push the pieces back together on the bowl, so if they fell they wouldn't be in a shape that would facilitate rolling.
Live, learn, love hookah.