My post will be divided in two. First, the data about BPs before buying them and second the ones you get via star system reputation/influence.
As in many games, crafting is a way to get nice items at your level, and in WH40KIM it is confirmed (and it evolutes with your actual Inquisitor level, whichh is nice). The big "issue" I have here is that you need to learn the blueprint before knowing its actual level or even the class concerned by. I am actually playing a Crusader and I know enought of 40K to get that a sniper rifle is for assassins. For a person not knowing much of the game, since your Melee character can equip guns etc, I am not sure it's an evidence as for me. And the level should be also indicated, because I was happy to learn boltpistol BP at I1 or I2, waited an hour to get it done to discover it's available for level 7. In my opinion, I would have bought it at end of level 6/beginning of level 7, but would have dedicated my gold at I1/I2 for something more useful.
So I believe it could be nice to indicate class (if specific) and minimum level required on the BPs.
Systems influence and BPs
I got a purple BP when I reached 200 Influence in Chernobog. HOURRA! it's my first! And it's.. "needler sniper rifle".. requires background : assassin.. But but but.. I am a Crusader. I believe it's a random BP, but, maybe for the ones acquired via Influence, it could be nice to get a BP from the class you are playing, or at least, not from a class you don't play.