Stealing an NPC station - blocking all connectors and the door from other engineers
You can prevent other engineers from accessing connectors on a station by building a connector with a battery and timers. Set the timer to trigger immediately with a command to lock the connector. Tow it into place over a station's connector. This renders the auto-unlock on the station ineffective.
I have tested dislodging the connector by flying another ship against it and waiting for the unlock to trigger. It re-locks immediately so there seems to be no way to remove it.
An engineer could lock out everyone else in this way. You could also build it to have a second connector facing outward, allowing your own ship to dock. This would provide a free safe zone and permanent lock for your ships. You could also design the connector to have a long extension covering the station door, preventing others from accessing the station interior. The extension could have blocks on a rotor to make a door, granting you exclusive access to your new base.