Ive got a genuine nissan drivers side engine mount here at my place somewhere here u can have for cheaper than i bought it for.
when i pulled out my rb20det, the engine mount rubbers were shagged, so i bought both sides to replace em. Drivers side was impossible to get out, so we left it in, and replaced the passenger side one that was stuffed.
It pulled the metal away from the rubber (and the stud with it) like yours, meaning your motor is just resting on the passenger mount Take it easy till you fix it....
Pm me if you want the drivers side mount.
Id agree with the gearbox mount, as mine was also stuffed when i pulled the box out with the motor. I replaced it with a urethane mission mount, but i must admit it does add some vibrations to the ride....stick with std, or Nismo ones if you must upgrade.