Yep what you have there is your classic duel bolter wielding Space Wolf badass.
If i had to make him look less like a Space Marine and more like a Rogue Trader i would do the following.
- Remove the backpack and fill down the square bit its attached too.
- Remove both bolters and have him wield some non Space Marine weapons. Maybe a cutless and old flitlock pistol. Or maybe give him a choas marine plasma pistol. From memory they have all wires and tubes modelled on so they look a lot like the kind of Archotech a Rogue Trader would use.
- Give him a cape. Capes are badass.
- Whats really going to make him seem like a Rogue Trader is the paintjob. If you paint his armour with all intricate swirls and lovely stuff like that he won't just looking like a bog standard Space Marine.
Otherwise if you were to use him as a Space Marine/Wolf he would look awesome in any unit.