I like the third one a lot, but I would leave the wings overlapping on the top like the 2nd one. I think it gives a nice depth. I'd also suggest having all the antennae create the same shape (the free ones) for symmetry and balance.
I can envision the yin yang being is a classic black and white with the bodies and outline of the dragonflies in dark green or another subtle dark color.. The bright colored wings of the dragonflies (in hot colors like red, orange, and yellow) overlap the yin yang giving yet another balance to the meaning.