Hi David, I've just gone through reading all of the lore through this post, in the hopes that I wouldn't ask an already answered question (so sorry about this if you have).
Np, I love rambling about this stuff. (Though I will try to avoid infodumping too much outside of the game itself. There's always a balance to be struck & etc.)
The main question I had was about the reliance on these autofactories. At what level of technology would the sector be at if all of a sudden these factories were to disappear? Would the current inhabitants of the sector be able to build (an albeit shoddy) space worthy vehicles?
The most advanced industrial planets could produce space vehicles. Probably nothing that could seriously stand up in combat to Domain-era ships, and probably not FTL drives. Maybe. They'd probably also have to devote a significant portion of their industrial and scientific base toward the project in the face of an almost surely unruly population, possibility of starvation, degrading terraforming systems that must be maintained to survive, threats from neighbours and internal factions, and all sorts of problems.
For a rough analog: the United States has had the technology to build a base on the moon and send people to Mars for quite some time. It'd be super difficult, expensive, and dangerous, but it's all very possible. Why hasn't it been done? -- Lots of reasons! And anyway there are (understandably) far more pressing matters given higher priority by the political bodies that run the US.
Basically, it's not enough to just have the theories and (some of) the technology required to rebuild the empire of the Domain. It requires the political will, the economic capacity, and stability enough to invest in a huge project that will not see returns for a long, long time.
I do read sci-fi on occasion; and found myself really enjoying Peter F Hamilton's Commonwealth Universe (Pandora's Star, Judas Unchained and the Void trilogy). I'm tempted to give Alastair Reynolds a read, though i'm a little wary of anything a bit too dark (eg Game of Thrones in space). How would you rate the universe:
Haha. Let's see, how about ... somewhere between 3 and 5? Someone who likes dark stories less would probably rate them higher on the scale. Let me explain.
Ultimately, the tone is not hopeless, but Reynolds stories are not warm and fuzzy. At all.
Many of the characters are deeply cynical and will betray one another. Sometimes the most likeable character in the story is at best "cold, but not awful". Characterization in the first book or so is pretty rough and none of the characters are easily likeable, though there's at least a viewpoint to root for; you can tell it's his first novel.
I would recommend starting at "Chasm City" then seeing how you feel about the setting. It is dark though; a good bit of violence and killing and a handful of rather sociopathic characters who do some awful things. Humanity doesn't come off well in the setting either - civil war, exploitation, huge and bloody divide between rich and poor, etc. Which I suppose could describe most of Reynolds stories, but I think this one pulls together the inner character and outer adventure narrative threads rather neatly.
(As a side note, I've not read any of Hamilton's work! It's on my list to check out. Just need to finish Blindsight and the Ancillary Justice trilogy first ... )