Two comments on the idea of the overlapping diffuse circles:
You basically took the color wheel and made it grey scale for #13, right? May be a coincidence, but I love the color wheel (below). But if you look at a color color wheel there is a slight difference in the center - where all the colors overlap in equal amounts there is pure white. So I wonder if we could do something similar where we assign varying degrees of the grey scale to where the six (3 primary and 3 complementary) colors are on the wheel, and leave the middle white. Does that make ANY sense?
http://www.google.com/imgres?imgurl=http://www.tutorials4u.com/html/graphics/rgb-colour-system.gif&imgrefurl=http://www.tutorials4u.com/html/tutorial-04-colour.htm&h=260&w=246&sz=4&tbnid=tuxZJSGpnexSjM:&tbnh=90&tbnw=85&prev=/search%3Fq%3Dcolor%2Bwheel,%2Boverlapping%26tbm%3Disch%26tbo%3Du&zoom=1&q=color+wheel,+overlapping&docid=tFpQNZugFHtqtM&sa=X&ei=J8mdT9WoLY-40QHx-6mkDw&ved=0CDEQ9QEwAg&dur=550Secondly, you have the other design where the circles are in an array. My issue with these is that they look like planets trying to line up, or lining up. Is there a way to slightly alter the array so this isn't the case?
#84, if you lost the symbol and put the letters atop that slightly glowing area that might the cool. But I'd like to see the light effect a bit more clearly. To that, the notion of putting the logo across something that looks like diffusion might work.
#82...similar to above, could you put the logo across a single circle of diffusion? in the circle there could be layers of circles, but the overall outline should be a single circle. Circles within a circle... don't think I'm making much sense.
Anyway, hope this helps in some way.