Back to my suggetions, to make liners stronger and unique.
Here are suggestions for liner turrets:
Liner Turret Level 1
damage: 160/320
range: 1500 m
velocity: 1100 m/s
refire rate: 4.00
energy: 500
Liner Turret Level 2
damage: 300/600
range: 1800 m
velocity: 1200 m/s
refire rate: 2.00
energy: 1000
Additionally a liner shield with capacity of 150.000. This shield can be named as "Liner License" and will be sold, where Liners are available. Costs: 100.000.000 maybe. The infocard of the Liner license/shield should show, you must have it, when owning a liner and its prohibited to use this License along with other ship classes than Liners.
Also reduce the cargo capacity to 1/2 or 2/3 as they have now.
This will solve the problem Nexus has with the current liners, without overpowering them and will avoid Liner whoring for simple trading purposes.