My personal opinion: Barges should not be used for cloak hauling or jumpdrive powertrading; they have a wonderful potential for very fun roleplay, and I love nothing more than mining for a barge convoy, and watching them slowly fly away, hauling the old-fashioned way and talking on their very long trip.
From reading the possibilities, this is what I believe would be best:
6: Prohibit docking barges on anything, requiring a smaller transport to work together with the barge
And, also, I believe that barges should be unable to be jumped. Jumping barges is complete powertrading, and removes the fun of flying back and forth between destinations.
Of course, to compensate for this, the barge should be given a bit more armor for surviving long journeys, and a bit more cargo to make the very long travel time, and extra effort of requiring another person to unload it, still profitable.
At the moment (without jumping) a 5k transport is more profitable than a barge, as it reaches the destination much quicker, with use of faster engines and tradelanes.
Basically:
Negative nerfs for barges:
Disallow docking
Disallow jump drives
Positive nerfs for barges:
Increase armor
Increase cargo (from 40k to 60k)
Remove ridiculous spinning
At first a person may think: "60k cargo OP!"... But, consider this: Barge flies at 90 m/s max, while a 5k transport flies at 350 m/s minimum (cruising) and over 1,000 m/s in tradelanes for most of its route.