Sounds interesting to me. So you must be talking about quite a decent size mill--not just a 30" diam. toy like I'm messin' with right now.
45 degrees is OK but will still be really going and putting a lot of tower load I think. It only slows down some. Similar to a 45 degree tilt back furling mill.
Just a little idea I wanted to try but never got around to it yet,, is to use the swinging furling action (with dampener) to employ a 'Shorting switch' as it furls upward thereby (seemingly) controlling it safer and far less tower loading.
Since I'm a cheap skate, I was thinking about first trying to short piece of copper pipe layed sideways up on the furling mechanism--and have it short with the brass (3-phase wire) connector bolt heads as it furls up. But the really big AMPS from a 12v big mill would probably melt it -- not sure. Maybe 24v system would be OK with less arcing??
Or perhaps a micro/magnet switch that controls 3 big amp solid state relays to short the coils during a big wind gust as it furls up. I believe the Skystream 3.7 downwind mill has NO furling and uses a 'shorting' method to control it in big winds.
From my little experience with my small 4' diam downwind mill, I would certainly put the yaw axis on ball or taper bearings. (or just use a trailer hub)
Downwind mills have a hard time turning (yawing) wide angles when stopped. Thats why I switched to the UPwind mills. (until I can make a downwind mill w/ball bearing yawing that is)
I would be very surprised if the Skystream 3.7 don't have a problem with that since it is a down-wind turbine with passive yawing. I presume it has taper bearing yawing for that 170lbs of weight. But I love the looks of it I must say.
There is not much anyone can do with a stop-n-go, up-n-down turbulant location I'm afraid. I just accept the fact that there is only half (or less) watt hours per day myself. I keep my mill low to the ground to hopefully avoid the wrath of my neihbors. I hate having to do it.
-Good luck with your project.