Just regarding VTOL, we absolutely have figured out how to do it with quadcopter drones safely handling weights comparable to the largest birds, and it seems to me that scaling these up to carry humans will be relatively straightforward [0].
Why? Planes also have rapidly spinning blades, but the actual risk from getting hurt by the blades is probably two full orders of magnitude lower than the risk from the whole thing crashing into something at speed, which is an inherent risk when you have massive objects moving quickly, regardless of mechanism.
[0] https://en.wikipedia.org/wiki/Passenger_drone