Regarding Aiel DFs - Edit 1
Before modification by Nameless Ashaman at 12/08/2010 11:40:28 PM
It stands very likely that there must be a high ranking aiel DF close to Rand, as there has been an important DF of every other group close to either Rand (Dashiva, Elza, etc) or every group's leader (Sheriam, Alviarin, etc).
Maybe there is, or maybe the Aiel are unique in that they were better at keeping DF away due to their culture.
I believe we've had direct quotes in the books that DFs are extremely rare amongst the Aiel (from Hadnan Kadere, I think, and maybe elsewhere). More importantly, I believe the harsh tests of Rhuidean weed out any potential DFs from becoming clan chiefs or Wise Ones. You need a strong will to pass those and DFs are inherently weak.
I don't discount the possiblity that the harsh new reality Rand brought to the Aiel might put a Clan Chief or WO over the edge (probably with a misguided aim of preserving their people and culture), much like it broke a percentage of the spears. Still, I'd be very surpised if Sorilea, Rhuarc, or any of the other prominent Aiel characters turn out to be DFs. If they are, they're playing a very deep (and mostly incomprehensible) game.