The rulebooks are very poorly edited. For example, rules for choosing your starship crew are at starship generation, along with the rules for improving starship component, but the rules for improving your crew are at the starship damage section.
Also, boarding actions are calculated using the hull space of your starship, but some hull type come with component included and the starship hull space in their profile is reduced, which means you have to find the component in question and add the space taken by that component to the stat provided.
Also, Xenos starships don't come with their hull space stats, which is a bummer because they also have special rules that would affect how they behave in boarding actions, (I'm looking at you, orks). This is especially frustrating if you bought the battlefleet Koronus and the into the storm supplement hoping to play a campaign as freebooters only to find you can't get the stats for your kroozer or your brute ram ship.
I mean, yes, I can stat out these, but I paid 100 $ in supplemental material to not have to, and I still have to, that's what's frustrating.
Also, most tables in the book will have at least one line which is not justified with the rest, and most chapter will have a table entirely unjustified. It's not enough to make the whole thing unreadable, but it does make the whole thing seem unfinished.
I mean, The Riddle of Steel used to be a indy game, and it was better edited than that monstrous thing.
My advice is that you buy yourself Black crusade, if only for the more streamlined gameplay of that tittle, (but you will miss out on the starship combat rules presented by Rogue trader - which is by the way the worst offender for poor editing, I have found) and you use books like those written by Sandy Mitchell or Dan Abnett for fleshing your fluff. You can also get some idea fluffwise from the codexi and the lexicanum wiki.
I fled to chase dreams that I can't yet describe.
I wake up, shivers, I hope my dream wasn't you.
But son, your dad, it ain't me, it can't be.