I used to think it was a practical impossibility to get the prop to hold rock-steady in a magnetic balancer in any position you move it to, but after a winning pylon racer showed me how, now I can do it every time.

You are right about the heavy hub. Whatever angle a prop rotates to, that means the heavy part of the prop is at the six o'clock position. I use a dremel sanding drum to remove wood from the hub or blade root at that position. Just run a sight line straight down from the center of the prop shaft to the lowest point on the prop along that line, and sand off a bit of wood.

Make sure you ream or drill out your hub to fit the crankshaft BEFORE you try to balance the prop!

You will improve the efficiency of a wooden prop (Zinger, Topflite) significantly if you shape the tip to resemble the APC tip--that is a more or less parabolic arc from leading edge of prop to a point at the tip of the trailing edge. Also, you can reduce the thickness of the prop airfoil so as to get a very narrow featheredge at the TE, and a very tight radius round LE. This helps tremendously to reduce the drag of the prop, and boosts your rpms by at least a few hundred over an off-the-shelf prop.

All this can be done in half an hour using a dremel and/or drillpress sanding drum for the rough shaping, then hand-held or soft block fine grit for finishing. I usually finish with 3M sanding sponge (Home Depot) fine, then superfine, then 400 grit sandpaper. I remove 100% of the surface of the prop in this process, and end up with about half the weight of a stock prop. As long as you preserve the basic shape of the airfoil, all the wood you take off contributes to a more efficient (faster turning, more thrust, less noisy) prop.

You'll need at least a few coats of spray lacquer to seal the wood, and you can use this process to perfect your final balance. A light coat takes only a few minutes to dry. Your finished prop will be a thing of beauty, and your engine will love it even more than you do.