Can't it drop each package with a mini parachute from about roof-top level with good accuracy? Or even 10ft, just above the height of most kids, dogs, cars and adults.
Skycrane landing. I've been reading and reading and can't believe it hasn't been mentioned - the drone simply unreels the payload on a cable while hovering until it gets to the ground. Then you either detach the clips, or, use a disposable cable and just clip the wires at the drone-end (saves on possibly tangles).
As the regulatory and commercial frameworks evolve, I can see how buildings would have dedicated landing zones (likely on roofs)… the XXI century equivalent of mailboxes.
The whole thing shouldn't weigh very much, assuming it's limited to delivering lightweight objects, and the rotors could be covered with a screen. I don't see much potential for danger. The worst thing that could happen would be a total system failure causing it to drop out of the sky, and even that could probably be mitigated with something like a failsafe that deploys a parachute if the speed is too high.
It should be safer than multi-ton delivery trucks, which can and have killed people. I was a mailman at one time - we were required to get out and look behind the truck before backing up because a mailman once killed a toddler who wandered behind his truck (though I doubt very many carriers actually follow that rule).
