Date: 10 Sep 2011 19:21 Title: Tainted
This is a very interesting backstory as to how it was Q could've ended up being specially tasked with Earth. Certainly not something that Q would ever admit to, if he has any sense of shame about this (and it kind of looks like he does). This could explain why Q won't ever admit to actually liking anything about humanity--because that would also mean admitting the rest of the Continuum was right to teach him a lesson by sticking him with the responsibility of their care.
I was very surprised here to see the evidence of the Q Continuum having any sort of moral scruples about what Q did to the Tkon Empire and actually thinking that torturing and harming mortals--and the desire to do so--could possiby be a bad thing. "Our" Q never gave us any indication of that, but that could also be because "our" Q is indeed ruled by base desires (despite his claims that we are base). Perhaps the most surprising thing was to see Q regret his cruelty, not just the fact that 0 and company could've challenged the Continuum. That he could possibly feel that torture was wrong. That never stopped him on the show. Maybe he got cocky and "forgot" that he was being punished?
As to the mortal form Q had taken...in the Trek mythos, I'm wondering, was he a Voth in that moment? The Voth were driven offworld by the asteroid, I think, so there was in fact sentient life affected by the asteroid that struck Earth. (Or did you decide that "Distant Origins" is either incorrect or not part of your canon?)