After I posted about my "maiden" which was very similar to yours, a couple of people pointed out that the stock CG is too tail heavy - moved it forward 3/4" following Winglet's advice and while it still ground looped badly, it flew much better.
My maiden wasn't long enough to justify posting the video, pictures and the advice I was given in this thread
Great looking build, I hope you get it airborne soon!
I would try a no power glide as well, see if it still acts up without the prop wash. Isn't it pretty important to get the vertical stabalizers set up evenly? One might be causing more drag than the other?