You make some excellent points. I agree that I like Aughra being a “batty old star-watcher,” sort of like a female Yoda in a fantasy tale.
I’m not really sure about other races existing on Thra alongside the Gelfling. I’ll admit that I do not care for the proposed storyline for a possible sequel to The Dark Crystal; it didn’t seem to fit and made things more complicated. However, that doesn’t mean that on some other continent or island over the Silver Sea that another race couldn’t have developed beyond the purview of the Skeksis, urRu, or urSkeks. I find it hard to postulate on another intelligent race living in the same area as the Gelflings and Podlings because, even if the Skeksis had not initially messed with them, the garthim and other monsters would probably have interfered with that other race or races. And once the Gelfling were gone, the Skeksis started taking the Podlings, so I don’t see why they would’t have turned to another intelligent race for essence as well. But until it reached that point…yeah, I could see everyone turning a blind eye. They Gelflings themselves did that, to their regret.
My thought on why they leave Aughra alone (besides the fact that she was not a Gelfling)is because she is too powerful. Or maybe she used to be very powerful and the skeksis don’t know how much she has been diminished, so they err on the side of caution. She seems to be Neutral Neutral, perhaps, as D&D might say, but powerful enough to cause them problems if she wanted to. I think they try not to draw her attention, especially since both the Skeksis and the Mystics have a certain reverence for time, symbols, signs…they approach and interpret them differently, but the reverence is there.
It does bother me that it seems like she no longer cares about the Gelfling and does nothing to help them when the Skeksis start killing them, especially since she is depicted in WotDC and especially the Creation Myths to be so concerned for their well-being. My only explanation so far is this: either she got so wrapped up in her work that she became completely divorced from the world she was supposed to protect, or there was nothing she could do until the Great Conjunction. After all, it took the power of the Crystal plus the Great conjunction to split the Skeksis and urRu in the first place. I think that the reason Aughra and the urRu retreated and waited so long was because in order to put the two halves back together, they had to wait for the power of the next Great Conjunction, otherwise it wouldn’t have worked. Still doesn’t quite explain why they then did nothing to try to preserve the Gelfling until the last minute though…