I'm new to Rouge Trader and I was reading through the core rule book and I don't really understand what the aim of Rouge Trader is... I GM both DH and DW and I understand that they both work for the inquisition if various ways but RT, I can't seem to find any definitive idea on what you do in the game. Can somebody please help me in this regard?
Also how compatible is the system with DH? I can see my group alternating between RT and DH so it would be cool if they were to play both sides of the rogue trader / acolyte relationship. Would this play well? Or would the differences clash and make a complicated mess of dice, blood and rubber shavings?