Clearly while the Venetian merchant-adventurer is an inspiration for Rogue Trader, this would be an example of a really successful Rogue Trader dynasty or concern-
http://en.wikipedia.org/wiki/East_India_Company
Since they effectively-
Bribe local rulers for trade monopolies
Conquer India
Spark the American revolution
Cause a famine
Start the first Afghan war
Corrupt China with illegal opiuma and start the Opium Wars
All for PROFIT!
Running a Rogue Trader campaign based on the East India company would work really well- first contact with a Murghal-like confederation of worlds out in the Expanse. Perhaps they are like proto-Tau or Exodite Eldar-human-like aliens but backward and caste and clan driven. The local ruler is open minded and corruptable- selling them trading concessions in return for Imperial luxuries and rarities. The proto-Tau/ Murgals have some useful resource or luxury the Imperium loves - the most delicious Amasec perhaps whose drinking has a botox-like effect on lines and wrinkles? Not a true anti-agathic but one that gives the appearence of youth? And vice-versa, does some human staple like recaff or corpse-starch give addictingly powerful highs to the xenos who samples it?
So with an alien people you can keep all the racism and 'white-mans burden' to improve/exploit the proto-Tau. And while the 40Kverse doesnt really do miscegenation (Genestealers excepted), perhaps the more adventurous Rogue Traders discover they have half-human offspring- increased and prolonged Imperial contact creating an analogue to the Eurasians of India and the Far East in the 17-19th centuries.
Of course, with increasing social and economic Imperial power comes reaction from traditional forces- rebellion and attacks that the RT's must suppress. Is now the time they take the crown?
Then, when the Traders have had some success and established themselves, you throw in a new conflict- Adminstratum functionaries arriving to take the Imperiums share and regulate the RT's. Missionaries arriving to educate the populace to the glories of the Emperor and disapproving of the drug taking or exploitation of the natives, or perhaps condeming and leading witch hunts against the half-human caste.
Throw in rival Rogue traders competing, Ork Pirates and the ever present threat of internal betrayal or guilty conscience and you could have a campaign to last years.
Thoughts?
SJE