Hi Jaggernaut. Have you had the pickguard off to see if there are any loose grounding wires? I'm not familiar enough with the VM jags to know if the bridge or vibrato is grounded in the default configuration. That would be one possibility.
The scratchy sound can also be static build up on the pickguard area of the guitar. And using the vibrato causes the static to move around and is picked up by the electronics.
This will sound stupid but you can try getting a dryer sheet and rubbing it around on the pickguard and other plastic bits of the guitar. The dryer sheets eliminate the static build up from the plastics. Has worked on a few of my guitars.
