The Royal Canadian Mint has begun its "bullion DNA" program for 2014, as I pointed out earlier in the thread. You can use this technology to trace your gold back to the mint over the web to confirm each coin's authenticity.
The "conflict gold" gets mixed with other gold in the smelter such that a certain batch of coins would contain, for example, 2% taint that links to stolen property (that was labelled as "stolen" retroactively). A paper trails may very well exist between the stolen gold and your coin. [The bullion DNA links back to the batch of gold, and documents show exactly where the raw gold for that batch was procured from. The raw gold procured from Joe's Cash-4-Gold was later found to be stolen.]
I like the gold smelter analogy because bitcoin transactions are actually very similar. A bunch of gold (inputs) get melted down, and then recast as new coins (outputs). You can't talk about "this piece of gold" or "that piece of gold" after it has been melted and recast, but you can say that each newly-cast coins contain x% taint with the old coins. Bitcoin works the same way: during each transaction, the input coins get destroyed and new (output) coins get created. Links between coins (known as "taint") spread in the same way that gold atoms mix during the smelting process.
I liked you point that "overlords could care less about where the Au comes from." Indeed, all that matters is that its gold or bitcoin.
Bitcoin is a new technology and it brings up fear and uncertainty for many people. But if you look for an analogy to something you already understand (e.g., gold), then the concerns start to seem silly.