Currawong, I think you're making a LOT of assumptions here. Firstly in particular with the nozzles, they actually specify the droplet size already so they've clearly realised this is something that needs to be known and I don't think getting different nozzles to suit would be an extremely difficult task and likely DJI will sell these as accessories. In the manual it actually has 2 different nozzles specified, one at 130-250um and the other at 170-265um.
Secondly in regards to the Chemicals there are no doubt a bunch of reasons why they haven't bothered to register then for Aerial Application, you're taking the fact that they haven't as some proof of your opinion when you don't have nearly enough information.
Next up you pull $30 per hectare out your butt clearly.
Honestly, you've clearly made up your mind that there's no way a Drone can do what you do and are working facts to match your opinion and a whole bunch of hyperbole on top of it.