5.) If you have a bad ground aka "buzzz" and your guitar is noisy it is most likely due to either a poor solder connection, partial short or dirty ac power.
I have buzz and hum, even when the guitar is not plugged in. When I touch the metal part of the plugged in cable jack, not the tip (cable is plugged into the amp but NOT the guitar), OR any metal part on the amp, the buzz is GONE. Does that mean I have dirty AC power??
I checked the connection from bridge to jack on the guitar with a multimeter and it sems ok. I think
the guitar itself is grounded ok.
This has been really frustrating for me!