I have raised many ducks, but never for eggs. I always let them set and hatch their own, and pretty much stuck with breeds that did so. But they say that with chickens, egg production decreases ca. 20% over the previous year's production after each molt. So I imagine that the case would be...
Good question LOL! And I hear different stories about (hatchery-raised) mallard ducks. Some say no permit is need for them, others say you do need one, and maybe it varies from state to state or whether you just have a few or are raising and selling them.
What kind of quail? I've raised both Bobwhite and Coturnix (Japanese or pharaoh) quail. I found the former very difficult, plus you need a permit, whereas the latter are one of the easiest birds to raise and you don't need a permit.
You may have to "help" the duckling out by removing the shell from the head end of the egg so the baby can stretch its neck out and breathe. I know that this isn't ideal, and there will be bleeding from the shell, but it can be very hard to get conditions just right for waterfowl in a still air...