There is always a risk. I worry about my 9 pound boys falling off the couch. The one likes to flip on his back for belly rubs and counts on the human spotting him. When my brothers visit, I have to supervise closely.
I put my bed on the floor when we first brought Max home and I've kept it there.
We probably should have trained for stairs, but my boys are nuts together and would probably still wrestle each other off the side of the bed, or take flying leaps to be the first to bark at the garbage truck.