Nylocks or loctite will prevent things coming off even if it comes loose from compressing the wood ( which the gyroscopic forces will most likely do even if the wood doesn't shrink).

This is a silly issue and can easily be solved, same thing for the tail hinge ( only ever used that construction on 2 tiny machine.

The furling issue is a much more concerning thing to me. I really do wonder how many of these things actually furl rather than rely on stall limiting.

I don't know whether we are going below the critical offset or whether the tails are just far too heavy. I have always got away with 1/" per foot offset but I don't think there is much in hand. One machine  built as a 4ft machine with the intention of modifying the alternator to take 5ft later and I based the offset on this. I got a better result from the alternator modification than expected and went for 5'6" and it doesn't furl. The tail goes over at a fair angle but the power keeps rising. It is on a site with little real wind and hasn't come to harm but I know it wouldn't survive a normal site.

With the inclined hinge restoring force I am convinced that once it does properly furl you will see a drop in power. ( I have to try very hard not to let this drop not to become too great but fiddling with the restoring force). If it doesn't drop then I think you are not furling properly although it may be helping the stall control.

With my methods of loading where I am away from stall the drop in power may be partly due to the fact that once you overcome the seeking force it puts part of the blade in stall and the power drops. There is no real drop in power until the tail gets to about 45 deg and then it seem to defeat the seeking force and power drops.

If the seeking force is much lower with the blades stalled then the transition as it comes into furling may not be so sharp but I can't believe that the power will not drop to some extent.