There is a possibility that drones from the same colony will mate with a new queen but the more hives within a 2-3 mile proximity reduces that greatly. Sounds like you have an abundance of diversity as any hives within 2 miles should be counted as providing drones for mating to your hives.
The best dogs I've ever had were all mutts (mixed breeds) and I'll say the same for bees. Some crossbreeds can produce a slightly aggressive hive now and then but it usually disappears with the next out cross (MH are a good example of this). Aggressive bees from inbreeding are much worse and harder to dilute by out breeding.