RodBromiley,
you have touched a nerve here it seems.
most people on here are keeping bees for honey so swarm control is necessary to obtain a crop so they will shoot your idea for that reason
apart from being a nuisance to the general public, it is not the most effective way to increase bee colonies. its a bit like fish spawning a 1000 ofspring to have 1 survive and procreate. with the diseases we have (imported) you are very likely to go from 1 colony to none as prime swarm is killed because in chimney, 1st cast dies in cold weather, 2nd cast dies of varroa and the parent hive succumbs because there is not a viable colony left.
by all means, buy yourself a piece of woodland, leave the old trees to rot and seed it with bees (check they are pure Amms though) and make it friendly for other pollinators. Yes they will incubate diseases that my bees will catch but I rest assured that they are more likely to catch that from mismanaged hives in my urban area.
personally, I see a guaranteed future for the honey bee rather in multiplying skilled beekeepers than feral colonies. Both can and should be able to co exist though.