We have chickens, indian runner ducks and australian spotted ducks. I free range them and they all go in the same coop at night. The ducks have enough floor space not to be underneath the chickens and i do not keep food/water in the coop overnight.
Having experienced trying to keep banty ducks with the tall girls though, I would be careful with the quail as I don't know how tuff they are. Sometimes the little guys get run over on the way to teh pool but all is fine in the coop.
I have never seen a drake attempt to breed a chicken, nor the other way around and do not believe they would attempt it. however, that is why i do not have a runner drake as I don't want to risk injury to my banty duck.