OK, a few hints from u guys brings a few improvements:
1) Create a lip around the outside of the rotor. Helps to hold the magnets in from flying away when at high speed (place outside of of magnets at 11.875" OD on a 12" rotor).
2) Use smaller wedges -- like (16) 22.5 degree 8" OD x 4" ID wedges on a 12" rotor (see attached). This creates some gap between the magnets to better concentrate the flux intercepted by the stator.
3) Create a method to mechanically separate these rotors from each other down the road. Realize these magnets are serious stuff -- it will take more than a hard tug to get them apart.
4) Start small and learn more along the way before you jump into the big stuff and build something you can't even effectively use.
All good advice for me - THANKS! Except I'd struggle to do #4! Knowing me, I always do the super-extra-turbo version of anything (my razor has five blades not two, my kitchen table seats 12 for a family of 4, my car has a supercharger when I can't use that much power anyway, etc). I know that I SHOULD start small and be reasonable rather than be over the top. But then I wouldn't be me and I'd lose interest in the effort...
OK, OK though, I'll scale it back to 10' diameter blades instead of 20'. Actually -- I have no clue how to "size" the blades for this heavy rotor/magnet setup in a relatively low wind area (Ohio). Not even thinking about blades or towers yet -- just understanding the magnetics and electronics and mechanics for now. Maybe that's my first mistake.