Kruger can engage in piracy against IMG and GMG in Omegas and SigmaS. Are Pirating are just demend cargo and money, or i can RP like Kruger competitor liquidator and shoot them?
This applies to any IDs that allow you to engage in piracy as well:
If the ID says you're allowed to pirate people, that means demanding cargo or money (or possibly some roleplay things, such as insulting their own corporation in system chat).
If the ID does not specifically say you may treat transports as combat targets, then no, you can't act as a liquidator. If it does say you can treat them as combat targets, then yes, you can simply kill them without demanding anything.
You: Hey, IMG guy. Stop it.
You: Hand me 5 million (or another demand) or I shoot you.
Option 1: IMG: Ehm, okay... I pay. (sends 5 mils) => you cannot shoot him; Once the demand is met, you have to let the transport go. "Halt" or "Stop" is not a demand.
Option 2: IMG tries to run away, does not reply, does not stop when told again => toast him
Option 3: IMG shoots you => toast him
And... careful, too high demands can be sanctionable.
And: When players think that you are not there to ruin their fun and if you do not make horrendous demands, generally players are more ready to pay up instead of making ships to hunt you, avoid you by player list, etc.
Plus: When you do nice roleplay, people will be less likely to see a LOL-pirate in you and also treat you with respect and roleplay with you.