so far the most entertaining idea i can think of and make work is a heretical (not the typical, RIP AND TEAR, JUST AS PLANNED, FUCK EVERYTHING I SEE twice, DEATH AND DECAY, kind of chaos heretical, just heretical enough) band of mercs put together as an extreme comically functional crew.
The Cook: Kroot named Cookie
The Weapon's Specialist: A tau that was dishonorably discharged for his high resistance to the ethereal caste's mind control, and his unusual capitalistic views
The mechanics: A mekboy and techpriest, the mekboy works on the ship's weaponry, the techpriest works on the ship's general hull
The "janitor": A daemon host that has possesed a ship maintenance servitor
Combat A.I. system: It controls the combat servitor(s), and is called G.I.R. find something that G.I.R. stands for and it's all good
The navigator: A blazed, high, drunk, eldar farseer that was kicked out of farseeing school for his bad habits, still a grade A farseer though, just a wee-bit off at times.
The translator: A seemingly sentient Necron. He has no beef with the eldar but the eldar gets creeped out and moody if he is near. The necron just kind of is along for the ride
The Captain: I like the idea of cultist chan being the captain, just because no one really hates her, she's a kid, and hell, the shits and giggles that would ensue from her being captain would be quite well, shitty and giggly .......