But I guess if you take many enough shots, you'll hit something at some point. xD

Haha, point! :D

But then how pure are the yao in this context? Is there some kind of hierarchy, or is it just 'gui = filthy, literally everyone else = pure'?

I'm not sure about the yao. But humans are contaminated with the three worms, so they're not the purest at any rate.

Like, it could go straight from 'unfamiliar' to 'I know what it says', without the process of actively reading it.

Oh yeah, great point! I wish we knew more about that language, too!