In my opinion there should be an additional character progression path for Klingons as well, similar to the diplomacy expirience implemeted for the Federation faction.
Perhaps something like a glory rating, which can be increased by fighting randomly generated NPC captains acting as challengers in randomly generated space and ground missions provided by an NPC acting as a challenge broker. Fighting Klingon NPCs would also provide a possibility to accomplish accolades requiring defeating of Klingon Empire members.
This system could even be extended to include challenges to federation captains coming from Klingon NPCs, but in this case diplomacy expirience for Klingons should be implemented as well (diplomacy is not unknown to Klingons, since they at least have ambassadors).
What do you think about this?
This would be good to meet the challenge of rival houses and bring glory to the empire!
I'm inclined to suggest that in place of a Fed BO (or even a Fed ship), it should be a level scaling item set you get piece by piece at each rank and each piece should be stolen Federation technology you can cobble onto your ships.
For example, a set of harvested Federation nacelles (with some extra rugged bits of gear hanging off to show how it's cobbled on). Each item is level independent and reduces your transwarp cooldown by a % (Klingons need faster transwarp back home rather than transwarps to more locations, I think).
At the max rank, maybe you get a baldric covered in trophy Federation combadges of varying types and a Fek'Ihri BO that word of your fearsome legend has subdued into service.
I think there are some cross-faction BOs I could see being available to Klingons (ie. a Bajoran mercenary, etc.) But I tend to think perfect symmetry shouldn't be a goal with faction design and any cross-faction mercenaries should probably be a latinum reward rather than shoe-horned into something other than diplomacy, if it isn't actually diplomacy.
In terms of mercenary BOs, I'd probably have them wear off-duty uniforms as their defeault costume and go for something like:
The pool of mercenaries would include a balance of races who are traditionally from different factions this way. For races like Orion and Nausicaan, they'd get a choice between your faction's uniforms and their racial gear. For other races, they'dprobably be wearing the Mercenary C-Store set and have the option to wear your faction's uniform.