I am quite surprised that you are refuting my thesis by refering to a text that says exactly the same as me. Currency is not a means of storage of value or measure of value (I assume that those are the mysterious "2nd and 3rd meanings" you talk about). Storage of value is the same as having a defered exchange. For example: "I give you one pound of meat today for an iPod in a year" is the same as "I am selling you this meat for X simoleons and next year I buy an iPod for X simoleons". Measure of value is iffy at best, for the exact reason I described in my original post: the value of things fluctuates for many reasons and for no reason at all (aka whim or fashion).
Also, I cannot fathom why you would bring Zimbabwe hyper-inflation in a discussion about value and money. In fact, I am surprised a gold bug like you did not bring up the Weimar republic instead. It is self-evident that bad actors, be they governments or corporations, can ruin a whole economy. But Zimbabwe was never a credible government anyway.
Backing a currency on gold, at best, makes the operation of printing money more tedious because a government has to find more of the stuff before, and at worst strangles an expanding economy because value is created but gold cannot be. The only applicable patch would be deflation: since a finite amount of gold represents an expanding economy, everything must keep being "worth less" in gold for everything to balance. And since gold-backed currencies have worked by the principle of "fractional reserves" for a long time, they were a sham anyway.
As for a unique currency resolving poverty, I present you the perfect counter-argument: Rome, Medieval Europe and Renaissance Europe were full of poor people, even as currency was made of real commodities (mostly metals) and was directly convertible in useful objects in your smithy's backyard.