I work for one of the biggest global wind turbine manufacturers. On one hand I recognize that this is exactly how disruption happens- small player with a tremendous idea and the opportunity to utilize wind resources in areas where traditional turbine designs can't be sited.
On the other, I don't envy the engineering team their road ahead- I see firsthand how many challenges we face every day with "ground-based" turbines, and have an inkling of how difficult an engineering challenge this will be. Best of luck to them- anything that pushes renewables forward in a meaningful way is a win for everybody.
I do not believe you have built a windmill- you have built a proper wind turbine.
Very cool project- there are a good number of residential scale manufacturers out there, but I believe this is the first homebrew wind turbine I've seen.