I'd wrap some insulating tape around the braid at the jack socket end. You don't want it touching the tip connection by accident. The rest of that length should be OK.

As you are going for minimum hum pickup, I would have minimised the exposed length of pickup output wire connected to the volume pot to the bare minimum. Unless you are running short of overall pickup wire length, I'd cut it down and resolder. The length of the ground wire doesn't matter here, just the hot wire.