Yes, of course there would be problems with air traffic control, daredevil teens and texting flyers. I think you forget that practical technology brings with it the evolution of the technology and habits that regulate it and keep it safe. My grandparents drove home from town in straight lines across fields; roads got cut later. Traffic signals, speed limits, and vehicle inspections only developed out of the need the new technology created. So the new flying cars will be sold originally to rich heavily regulated few. Then they will develop failsafes, autopilot, and complex vehicle networking to maintain space between cars so that I can take off from home not the designated take off zone. We are in the end self regulating, it simply does not develop until the technology forces it to. Have hope, we can solve all your flying car concerns; We just will not know how until someone makes a flying car.