Look at this site. Its pretty interesting.

http://pr.erau.edu/~allenm/wing.html

Jim it seems that you have it right except for the aileron deflections. To get a favorable yaw on aileron control input (right roll causes the nose to yaw right also) the aileron on the left side needs to go down and the aileron on the right goes up. The right aileron works as expected when going upward. When the left aileron goes down it causes an increase in lift on the left wing tip area which because of the large wing tip twist gives you a vector forward which stops the adverse yaw.

The center of drag of their flying wing is aft of the CG which gives the baseline directional stability. Zagi and others use the tip fins for directional stability.

I would think that CG placement shouldn't be any more critical on it than any other flying wing. As long as you are adequately stable it would work.