Does a skinless fuselage add to the likeliness of an unrecoverable spin?
Well, I would solve with transparent Monokote if it was a model.  No accounting for people's taste.  

Although some very early aircraft featured that look, designers soon realized that covered "slab" sides not only reduced drag, but also improved directional stability.  Note that covered area aft of CG acts as an extension of the empennage, allowing for a smaller Vertical stabilizer.  Many 100 years ago were comparitively tiny.

As far as behavior in a spin, what he has on the tail may be sufficient for safety, as well as good CG management.   But I would certainly not recommend denuding your fuselage for a certain "look" without some expert advice and testing.

Designers do compare side area ahead of CG to aft of CG to estimate yawing tendency in a slip.  So he may be OK.