how do you plan to implement these features through mod programming?
Through a stuff-ton of GUI's and databases. The company GUI has a lot of preferences to lay off or demote players depending on when they last did their job. The manufacturing GUI is basically just a spreadsheet with a list of every manufacturable item and their inventory, quotas, and required resources. I'll post pics of the GUI's soon and it'll make more sense.
The crime system checks for witnesses whenever a crime is committed. If a player witnesses a crime or discovers evidence they can report it at the police station or through their cellphone (if purchased). If a policeman witnesses a crime or discovers evidence the criminal will get demerits instantly.
Self defense is pretty simple as it just checks if the offending player recently damaged you, stole from you, molested you, etc. and allows you to damage them in return without counting as a crime.