#5
I don't think it would hurt to run a ground around all the pots, but I think the metal plate they are attached to is acting as the ground for that. You may have a break inside the jacket of one of your groundwires. If you have any decent length of wire maybe with alligator clips attached to each end you could jumper your bridge to the back of a pot or that central ground and see if it stops it, if it does try replacing the ground wire to the bridge. If it doesn't try the same thing to the toggle switch, etc. Another thing to check is if the wires to the jack may be reversed.
#6
The metal plate definitely looks to be the common ground for the pots. You could run a wire to each pot for grounding, but I don't think it would help at all. If you have a multimeter, put one end on the bridge and the other to this plate. See if it "rings" together. If Gibson grounds like every other guitar maker (which I'm sure they do) there should be a ground wire from the electronics to the bridge, either the stop tail or the tuneomatic bit.
If it doesn't ring, you may need to figure out how to re-run this ground.
Harmony: Stratocaster
Alvarez: F-200
Schecter: Omen 6
Fender: BXR-60
Dean: Metalman Z Bass (Betty)
Egnator: Tweaker 15
Pearl: Maximum
ESP/LTD: EXP-300
Custom: Harley Quinn Bass
Custom: TK-421 Explorer
A steadily growing supply of pedals
#7
This white wire looks like your ground to the bridge, hard to tell without knowing which way is up.
Attachments:
IMG_20140807_171654_zpsf7ad9c67.jpg
Harmony: Stratocaster
Alvarez: F-200
Schecter: Omen 6
Fender: BXR-60
Dean: Metalman Z Bass (Betty)
Egnator: Tweaker 15
Pearl: Maximum
ESP/LTD: EXP-300
Custom: Harley Quinn Bass
Custom: TK-421 Explorer
A steadily growing supply of pedals