All right, So I wanted to run Rogue Trader but the book is basically rough draft version 2 of Dark Heresy 2nd Ed.

Then I got thinking to myself what does Rogue Trader actually offer inside the book?

Do the Careers matter? No, not really once ship roles were introduced the career just became some stat weights.

What about the Origin Paths? Well I do actually enjoy those. However in reality DH2's Homeworld, Background, and Role accomplish the same thing but make each choice more impactful (and it means I don't need to homebrew Aptitudes)

What of Profit Factor, You can't be a Trader without Profits?! Couldn't agree more. How convenient that Influence and Profit Factor are seamlessly hot swappable. Like literally nothing needed to be changed other than you don't have individual Influence scores. You just keep using the chart on Rogue Trader page 272.  For this DH2 rarities will take precedent.

Space Ships? Another spot where the two games are so close that it's not even worth changing anything. Literally the only noticeable change is that you can just BUY your Piloting up to +30 rather than painstakingly altering your background to give it to you for free.

Aliens? Everyone banned them anyway. However they are actually pretty easy to slot in. Way I see it it really only needs to be a Background. Most aliens have sufficiently varies origins that Homeworlds as they stand fit (Forge world could be Bork’an Sept for example) and while I wouldn't trust a Kroot Doctor or allow a Tau Mystic the Roles are generally versatile enough to cover what you might want.

Navigators? See aliens above. Everyone has a image of what a Navigator does in their head but the stock Navigator isn't a character, they are a plot device. So I look forward to seeing unique Navigators that are from their family holdings on some world and are interested in acting in some Role. Navigator powers are easily converted (in that they don't need any changes) plus lucky you! You don't have to get one power upgrade every 2000xp or whatever you spend.

In reply to Space Between (msg # 1):

Tl;dr
This is a Dark Heresy 2 game with Profit Factor instead of Influence, a couple Homebrewed Backgrounds, and space ship combat dropped in. Theme changed from Inquisition to Rogue Traders.