I was mainly using all that to make a point that gold is no better than bitcoins.
Which you failed to do.
There is a striking difference between BGC and BTC.
The BGC has a minimum lower value of whatever size chunk of gold a coin represents whereas a BTC has a minimum lower value of zero.
Why exactly can't gold be worth zero?
"Because it was always so", right? There is no non-zero minimum value for anything.
Besides, that wasn't what I said anyway. In my thought experiment I said "the gold vanishes". It mades no difference though, because nobody would know it'd vanished. So: people didn't want the physical gold, they wanted the promise that the issuer couldn't magic more gold from thin air, they wanted something that could be used for trade. Bitcoin can supply those properties, so what do we need gold for?
I'm trying to show that if gold were easily tradeable via trusted certificates (or a bitgold chain), nobody would ever want to redeem their certificate for physical gold. Therefore
they didn't want gold; they wanted some of the properties of gold.