I made a mod over at lucasforums that includes Pirates as playable along with rebels and imperials. The first issue is is that Pirates can't build units. Pirate bases and asteroid boses dont come prewired to build units. Also, the lack of an AI file stops expanision. Though rebels and imperials will build pirate units/ venators as they see fit if they are made available to them. In my mod imperials have venators, and they build them along with acclamators, and before that while I was getting things to work, the Rebs/Imps would use preety much everything pirates. Perhaps someone can do something. I know my mod will not handle it.