Some thoughts to make them more stock-pirate-y. They're rather well equipped for pirates right now if you ask me.
Interceptor; maybe replace the front flaks with pulseguns or mining beams, so it can also act as a light skirmisher. PD-dedicated ships tend to be of little use, and the other ships are already PD-heavy. Alternately, replace the outer flaks with wide arc (215?) pulse guns/mining beams.
Armoured Interceptor; again consider replacing either the forward diagonal or forward straight flaks with either pulse guns or mining beams so it can return fire. I think I see a blaster hiding under the core sprite...
Armoured Attack Ship; drop the two forward blasters, two of the particle guns and one of the deflectors (as they're rare on pirate ships). Perhaps only use one mining beam in the center rather than two.
Assault Frigate; drop the outermost missile launchers and innermost blasters, and swap the six scatterbeams for four mining beams - two to each side and two facing diagonally. Possibly drop two of the particle guns and one of the deflectors? Move the flak forward and place a single deflector where it is now, possibly a little further back so it can be shot down that narrow 'vent'.
Broadsider; drop both the center of group pulseguns and center of group mining beams. Angle the mining beams outwards a little, and angle the pulseguns a little further forward for better frontal defense. Delete the boosters and place them again for proper appearance.
Heavy Bombardment; drop between one and two particle guns. Maybe add a fifth mining beam to the core, or drop a beamer and move the other to the core and add mining beams to replace the beamer's previous locations.
) and to not use any weapons that I would classify as 'alien'. Now that I think about it though, I suppose scatterbeams could be considered alien.
