One point I’d add other than heartily recommending this for any strategy/empire building/ (slightly) tactical space battles is to make sure and visit the developers forums at http://www.kerberos-productions.com/forums and read some of the additional background lore. Easiest way to find it is to simply do a search for posts by Erinys, she’s the writer behind the series.
A lot of it’s been fleshed out on the fly but not in a haphazard way. Fortunately the sequel is going to include an encyclopedia.