I dont see why the built in charge controller shouldn't work fine. I doubt that turning it all the way up and adding a second charge controller would improve things, but I could be wrong.
Regarding Aluminum blades - I think Aluminum is not a good material for wind turbine blades. I would expect problems with metal fatigue over time. I also think that the blades should be thicker in some places than others. Something made from sheet metal, thats the same thickness all over is not likely to make a good airfoil. Thats my thought on it. Some feel differently - I think tlg has lots of happy customers and I expect if they were having problems they'd probably say something or rectify them. Its not the approach I'd take though.