I think that an ex-pirate is a fine addition to the group, but yeah, this is a 'regular' (as much as such applies in the Alliance) 'line' (same) unit of the Rebel Alliance Army. There's no doubting that someone with a background in piracy can be very useful, but these characters are part of a platoon in the war as a matter of organizing the whole thing to keep it cohesive.
Edit: The Intruder could easily be an ex-pirate ship, however, crewed by ex-pirates. That'd make for an amusing backstory as the opinion of the infantry about the freebooting supplemental activities of their Naval counterparts is less than legal in a lot of ways. Also, black marketeering, which goes hand in hand with the Hutt someone proposed as a character. It might just be the remnant of a Hutt Cartel operation that had nowhere to go but the Alliance Navy, especially since someone else proposed a Hutt on board.
That'd give the whole ship a sideline -- black marketeering and various profit-motivated enterprises as a supplement to their naval operations. They'd have to cut in the platoon, as they're the boarding force and security.
That'd be an interesting idea to play with, especially if any of the rebels are ex-militia or really high morals and then suddenly they're on an ex-pirate ship that still won't be exactly squeeky clean.


