Okay, I'm spending my time now desperately trying to answer all those questions that have arisen regarding my setting. Along with several of my answers, I've made myself a note to "leave this nebulous in the novel," or a recommendation that I "probably shouldn't resolve this question within this book." This is valid: just because I understand how the world works doesn't mean I want the reader to comprehend it all immediately (or, in some cases, ever). In my novel, the reader discovers facts about "reality" along with the protagonist, and there are some things the protag will continue to guess about, or perhaps never nail down.
But I have to pull off this "setting mystique" without giving the impression that I myself simply have no clue what's going on.
I've said before that I wonder whether Lucas knew Vader was Luke's father from the opening crawl of Episode IV. (The Dark Lord's name does suggest that he did.) I'm virtually certain he didn't know what the "Clone Wars" were when he had Leia make that seemingly throw-away reference in the famous holographic message, and that idea turned into a few movies and a television series. So I'm not meaning to imply that I have to understand my setting "down to the subatomic level." I just need to avoid the impression of "hand-waving."
Any time I have an opportunity to explain something about my world to the reader and don't do it, I run the risk of making the reader think I'm being ambiguous because I just don't know the answer myself. So the trick in a novel like Bring Me to Life, which has significant elements of a "Steam-Grommet Factory" story, is to keep the reader just enough in the fog to be entertaining without being annoying.
To do that, I need to ensure I myself know "enough" about the setting. So the mental exploration, and the struggle to define "enough," continues...