A Dauntless class Light Cruiser has been spat out of the Warp, after disappearing off the face of the Imperial map, drifting helplessly through space as it's engines have all but been destroyed by the ravages of the Immaterium.
How is that even possible? DDid the ships geller field fail and allow the denizens of the warp to wreak havoc on the ship? And is it the warp engines or regular engines that were damaged or both? Because if the warp engines were damaged then how did the ship make it back to realspace?
But due to its remote location, far from the Emperor's reach,
You don't need much more after this honestly, assuming you mean beyond the light of the astronomicon (it fits with what your going for since Imperial ships are hard pressed to navigate without that.)
he knows somethings up when he is allowed to pull his ship right along side the other craft without taking a single shell.
Why? Ships go missing or suffer a terrible fate that renders them hulks fairly often, its a big galaxy after all. Its just another dead ship ripe for looting or a good scrap.
No Mecs or vehicles allowed, these are halls of a ship after all, not an open battle field.
Ships in 40k are quite large, in fact everything is. It wouldn't be all to surprising if you were able to drive a tank down the central spine corridor of a cruiser.
A paragraph is the bare minimum I want, I'm not looking for huge posts telling me how exactly your Ork managed to cut someone's guts out with a toothpick, but any flavour text is appreciated though.
Yeah..you do understand how vague the size of a paragraph is right? Are you looking for four sentences (the minimum allowed in this sub forum regardless), five, ten, or twenty?
Just a bit of a nit pick, its shoota not shotta.
Age: (Do Orks even have ages?)
This is assuming Orks can count, and then that such a concept as age actually matters (which it doesn't to Orks.) I'd suggest just removing it.