Do you think that Threshold, Low Red Moon, and Daughter of Hounds would be a good place to start someone on your work, or would you recommend a different order/combination/whatever?

I would say, at this point in my career, looking back at the books, begin with Daughter of Hounds, then read Low Red Moon and Threshold as "prequels."

The intersections in your post made me think of "Marys of the Sea."

Now, that's just flattery. :-)