Mine are local girls - I simply breed from what I perceive is the best queen or two each year. The idea is that, as I have a fair number of drones over 2 or sometimes 3 apiaries, they will feature fairly well in the mating mix but not enough to have any inbreeding as there will be other colonies around and about and the drones from them will give genetic diversity. I have sea a couple of miles to the east and a wide stretch of marsh or water to the north and west which is not good bee territory, so I would hopefully not see too many drones from a really large area as they would be inhibited from traveling across these. I've no idea where DCA's are though.
Grafts are a funny thing - I will report the same thing as you may have read elsewhere that if they are put in too early in the hive in spring or at the first attempt in a colony, the results can be very poor. Obviously if the colony is no way ready to produce queens - i.e. there are not drones in the hive which can be considered the first part of swarm preparation, they won't play ball. Other than that, I guess an average is 80% take-up - usually 9 are done at a time. Occasionally it's 100%. I think it depends on how clumsy I am with the paint brush I use for the larval transfer. I think it's fair to say - and I have no evidence to back this up, just anecdotal, that the take-up is generally better in a queenless colony that a queenright one. I guess that makes sense, as if we are talking about using the the supercedure impulse with a queenright colony compared to the emergency impulse with a queenless one, the bees won't really want to make loads of queencells.
May your bees read the same books as you do.