Why do many Jews have last names that have to do with money? Gold, Silver, and the derivatives... Goldberg, Silverstein, etc?

It all harks back to medieval times, when Christians weren't allowed to borrown money from other Christians. That put Jews in the position of moneylenders. (Which, in turn, didn't do any favors for the perception of Jews. But we're talking about last names.)

So, when last names became a common thing, they were often created to suit one's profession, and Jews got stuck with money-related ones. It is what it is. It's our history. We live with it.

Did Eddie Mahoney, whose mother was Jewish, change his name to Eddie Money to get back to his roots?

We have two tickets to crazy town if you believe that.