I was Googling Glutathione and Copper and actually found this post of yours.
You are correct. Bile flow is very important. It is how we get rid of toxins. The lady I doing Nutritional Balancing with puts a lot of emphasis on getting bile flowing again. (lemon water, eating some grapefruit, coffee enemas, flushes)
For the last year or so, I get lots of gallbladder sounds under my right rib. At first I would only hear it during coffee enemas. Then I started to hear it during other times.
From 2008 to 2011, I did have a lot of the pale bowel movements. i.e. I was not releasing bile.
In addition to this post of yours, I also found the attached article in Journal of Biological Chemistry linking glutathione (lack of) to copper toxicity.