I've tried to post twice in reply to this and always forgot to save after the preview. :(
I can't recall all what I wrote. So just say that I've read it and that I basically agree with your call to prudence (so Virgoan!).
Anyhow, I'm sure it will be found a planet worth of ruling Virgo. You guys (and gals) may be perfectionist but not necessarily perfect yourselves (and you know better than anyone else - am I wrong?).
I still find Eris quite Libran: using sweetness (the golden apple "for the most beautiful one") to triumph magistrally in the social plane. On the other side it would be quite ironic that a sign that doesn't bear disputes (and tends to brush the trash under the carpet) would be ruled by the planet of discord precisely.
So I'm each day more inclined by a third way: that KBOs (all KBOs, Pluto included) are not the sign-rulers we are looking for but just advances of something to come.