I actually ended up telling them that it belonged to vulkan and they decided on there own to bring it to nocturne!  and basicly gave it to the salamanders for free ( though they did get a full merchant fleet from them because of it i felt i had to reward them for that)

oh were not seriously considering using the mass conveyer in combat its only to haul the junk around, we have a small fleet with 3 lunars 2 frigates and a transport of some kind, we were asking about the various races because we havent seen them in the books we have

You know your playing rogue trader when you have over a thousand jokearo on your ship but the captain still wants to "trade up"

Well, it's great if you're hauling junk around and have a lot of it. Terraforming equipment. Entire cities living in the void perhaps. It really depends on the kind of game you want to run.
 
If you want to be the equivalent of Honest Akbar's Galactic Discount Emporium then it's great, because there are deals on board that would blow your mind! Or maybe just eat it!
 
If you want to run a more violent, bloody game where combat is expected and you don't have any other ships then no, it's a terrible idea. It's not going to be able to effectively defend itself and if people fight to the death you will be boned.