When I’m sitting at idle in neutral I hear a metallic vibration like noise. If I push in the clutch it goes away. Is this caused from a lightweight flywheel? I was told by the previous owner that it has one, and I get the metallic bag of bolts rattling noise at low rpms in 1st so I’m sure he wasn’t lying.

 

Bad news - a metallic noise when the clutch is engaged means your pilot bushing is going out. Some folks opt for the Nismo needle bearing upgrade when they install a lightweight flywheel, and I've heard that they tend to fail prematurely.

I can't exactly blame Nismo for that, as in this case Nismo = racecar = willing to tear down and rebuild more often.

 

^^^ He is saying it makes the noise when he's not pressing in the clutch. It's really quiet when stock, and gets much louder when you install a lightweight flywheel. It's normal.