I was just thinking by combining the rogue trader Core book and some of the DH source books (Radicals Handbook) you could get an interesting game. A rogue trader and his crew are corupted by the warp and the powers of chaos, so they have daemon weapons and daemonhosts. They have to attack imperial worlds, shipping lanes, general chaosy piracy. Instead of Profit you could have notoriety. As you inflict more acts of terrorism and piracy your notoriety grows and you become more infavouse and other followers of chaos will join you. But beware, become to much of a threat and the Imperial Navy will hunt you and maybe an Inquisitor will be sent your way (Use Ascention). This would alow you to express your evil side and RP essentially a chaos cult...with a starship.
Anyway just an idea so what do you think