#6 is cool, but I wonder if it is an Asian symbol for something also. It would be good if the symbol signified something good like "valour," but not if it's something sketchy, like "cockroach" or something :-)
Thanks for responding to my comments on #12. The DH art component is strong and can be used as an Avicon. Can we experiment with ways of making the H a little clearer, perhaps with a blue left column (like the right column already is?). The red swoop of the D should give the D enough identity.