Wow, I'm learning some good stuff too. I might want to give an astral nation a swing next game. Mightypeon, you are indeed a mighty font of information for us noobs.
Communions are powerful and confusing, to be sure. Baalz wrote an excellent guide for them (http://forum.shrapnelgames.com/showthread.php?t=37499) which I would recommend for everyone to read at some point or another.