Just for a hoot, I've change the Campaign Options => General tab => Faction to "Pirate" in an ongoing 49.12 campaign. It seems to have trouble generating contracts, even manually. The log file had a number of mentions of no enemy available (kicking myself for not grabbing a copy before restarting). As far as I can tell, the ...\data\universe\factionhints.xml file is used to determine opponents for each faction. It only has one listing for PIR (mnemonic for pirate faction) as an <exception> element, like this:
<neutral faction="CS">
<exceptions>PIR,TD,GV,MV,BoS,MM,WOB,IND</exceptions>
<exceptions end="3012-01-01">OC</exceptions>
<exceptions start="3052-05-01">CJF,CW,CGB,CSJ,CSV,CNC,CDS</exceptions>
<exceptions start="3068-01-21">WOB</exceptions>
</neutral>
As I read that, ComStar is not neutral to pirates, which makes sense.
In order for "Pirate" to be a playable faction, there would need to be several entries added, at least one <rivals> like this:
<rivals>
<parties>PIR,FS</parties>
<parties>PIR,CC</parties>
<parties>PIR,FWL</parties>
<parties>PIR,LA</parties>
<parties>PIR,DC</parties>
... (most of the other factions)
</rivals>
... and possible a few <alliance> elements, indicating some of the minor pirate-friendly powers such as Circinus and the Tortuga Dominions which are less likely to be in conflict.
Does that look right?