Whee! Fun rant! I currently have two major female asexuals; in my world, all the really powerful mages have a genetic disorder (I said disorder and I meant disorder. My background's in biochem.) that causes extreme physical disabilities (think muscle wasting, heart disease, and immune system defects) and asexuality. It's my explanation for why such an adaptive mutation hasn't spread through the population. Coincidentally, one of the two is also a dragon philosopher, a.k.a. Point 1.