re 1: I doubt weight is the main concern with a helicopter style drone. I've seen some palm-sized hobbyist helis at the local field. I'd guess durability is the

re 1: I doubt weight is the main concern with a helicopter style drone. I've seen some palm-sized hobbyist helis at the local field. I'd guess durability is the larger concern. a quad with fixed rotors can take some pretty rough landings and still be good to go. the variable pitch mechanisms are much more delicate.