Mine would definitely fly off given half a chance in their first few months, we had to climb a neighbour's roof rescue one once! They now seem to think of their enclosure as their home and no longer keen to explore the big wide world.
One boy per at least four girls is less likely to cause trouble but the more girls the better, plus the hutch would need separate compartments in case some of the quail bully the others and don't let them shelter inside. I've had girl only groups but then a girl takes on the alpha role including beating up other girls. They do really injure each other badly!
If your run is on slabs chances are the bedding won't dry out well or at all in wet weather, and as quail are ground dwellers, not perchers, it'd really be better to keep the bedding dry. Easily solved by getting a wooden pallet from an industrial estate and covering that with rat proof mesh.
I really like my quail. Would you be hatching or buying in youngsters? The younger they are the easier to get them used to humans.