to answer the last...
gold is , to some extent, an inflation play.
it is a refuge to safety (a concrete asset vs. the dollar which is merely based on trust since the gold standard was evaporated).
when most people are talking about the EUR, they are talking about the EUR as related to the $$$, as in EURUSD.
if EURUSD is going higher, that means one Euro is buying more dollars. dollars are worth less in regards to the EURO.
if gold is going higher, that means an ounce (or any quantity) of gold is buying (can be exchanged for) more dollars.
so, to put it briefly - yes, there is correlation.
if ANY commodity is going up in price, that means (basically) that less of that commodity is equal to $1.
that's what inflation means - your dollar buys less of "stuff", whether that stuff be food, commodities, cars, or whatever.
similar commentary could be made regarding the oil contract.
i think people need to ALWAYS understand that correlation =/= causation
however, it is certainly true that smart traders can capitalize on intermarket divergences and/or foreshadowing to make an intermarket play.