That's some really cool stuff! I guess I'll throw in my 2 cents
Pros: Obviously everything you said is really useful. I like that it's brand new, so theres room for some seriously awesome technology to get involved. Also, It would be a great self defense tool if you for some reason weren't allowed to own a gun (got in trouble as a kid or something).
cons: These can still cause some serious damage, which is good if your in a self defense situation. But mostly kids are owners of paintball guns, and I wouldn't be surprised to see a few kids die from shooting their friends with these things in the face. like Dune said, it's like a firearm, but giving a poorly trained kid a "firearm" is just asking for trouble!
I hope I gave everyone a little more to think about. I think it might be best kept as a secret, and not widely promoted, because thats when the damage is done. I still love the idea though! Makes me wish I hadn't sold my paintball gun