One thing I've always been curious about, has anyone been able to pull off such a campaign? I had been hoping Hostile Aquisitions would add some official rules for something like this (with the possibilities of pirates, privateers and such, I thought they may be some options for playing people who either don't have Writs, or have means below the standard backing of the Imperium...), but no such luck.
What I'm thinking is more Rogue Trader: Firefly Edition. The main issue I see to this is the fact there's no way of being particularly hard up - you either have an amazing ship, and little money, or a little ship with -tons- of money, and the means to easily supply whole armies with bolters and ammo. What would people recommend to limiting a Trader's means, to the point of really having to work for their stuff in the darkness (thickened with grimness)?