Why would a specialized sub-faction not sell weapons or ships?

+1 to a movable station and a rat subfaction. +1 for the station to be "hidden". +1 for the station selling rat specific ships and gear.

Just think of the ARK that Itanis used to flee from (then) Earth2... pirates found them, restored its power and now have their home "station"... since the Ark is said to be much larger than any existing station (shipyards is not a station)!

4th faction solves all IFF problems, gives reasons for someone become a pirate and would increase overall FUN!

A 4th faction would not even begin to solve all IFF problems, Alloh...

a 4th faction will solve a few IFF problems. The real IFF problem isn't IFF, it's the complete lack of meaning factions hold in gameplay. But that's a can of worms to be fixed soon (TM).