As I see it the issue with PvP crime and punishment is this.
As it stands the punishment is proportional to the profit to be made from crime, which seems reasonable till you realise that that's not how crime and punishment work. In a sensible system the punishment is based on the harm caused to the victim of the crime.
The solution to this is actually pretty straight forward. Increase the punishment for murder/piracy to reflect the damage to the victim, i.e. if the victim lost 2 mil in insurance and a further 1 mil in cargo the perpetrator would gain a 3 mil bounty.
You then, in the interest of balanced and interesting game play dramatically increase the potential profits to be made from piracy.
This is how I picture it working,
Player A interdicts player B and demands cargo. One of 2 things then happens (actually there are more possibilities but we are only interested in 2 of them)
1. B drops cargo which A then scoops. B gets to live and gets a portion (say 50%) of his cargo value returned through insurance. The insurance company then puts a bounty on the head of the pirate equal to the money they have paid out in insurance. However since this is less than the cargo value player A still makes a healthy profit.
2. B refuses and is destroyed. This is murder. A can try and get what cargo he can from the wreck but destruction of a ship is bad piracy. A can make some money but it will be less than the bounty now on his head.
Basically if the pirate messes up then they loose out, in the same way that a smuggler who gets scanned gets a fine (these too should be more substantial but that's a discussion for a different thread).
"But what of just plain old murder?" you say. Well for that you would just get a whopping great fine and no reward.
"But murder is a legitimate gameplay choice" you say. Yes it is but in no society is the punishment for murder a slap on the wrist. If you want to be a murderer that's fine but you need to accept the consequences. If you want to be a PvP murderer for "the challenge" (the main reason I see to justify it) then you should welcome the enormous bounty as it will attract people who make a living hunting wanted murders and who will provide you with a challenge. If you don't want that then what you actually want to do is pick on players who are weaker than yourself. That's fine too, I will defend to the death your right to be a prat, but there does need to be a punishment system in place for behaviour like that; and until there is many people will choose to play in Mobious or Solo.