This gave me goosebumps. I am always so happy to see people do good/nice things with their intelligence. I feel that drones and 3D printers still have tons of potential.
One thing that I love to see with 3D printers is the swift creation and very reasonable price of prosthetic limbs for both humans and animals/pets.
Drones are used in our area to inspect gas lines and electrical transmission lines instead of helicopters.
I have a very good idea for how drones can help protect ground troops but I have no idea on how to proceed to present the idea to the right authorities. I guess a google search will be a start.
Cool but they won't replace fire works. I'm looking at how many of those are being controlled at a time and thinking the only way they could do that, without interference between them, is through some kind of TDMA radio link setup where each drone had its own time slot on the frequency being used to control them.