I think ammunition would become the world currency. Especially 9mm and 12ga. That seems to be the thing to stock up on.
Civilization has to be intact for gold to be worth anything. Gold has no intrinsic value. You can't eat it or wear it, nor does it make for a more effective weapon than any other rock.
Not so sure.
Unless you destroy all civilization, everywhere.
Gold has been associated with wealth everywhere since the late Neolithic or Chalcolithic period dating back more than 6,000 years. Sure. Your most immediate concern is getting food and shelter, but I'd bet the widespread craving for gold for wealth and status would continue. What people will do to get that stuff defies all logic. And as long as enough people desire it, it actually has value.
Other than "desireability", gold has a few other unique attributes that come to mind:
1. It resists oxidation and corrosion far better than other metals.
2. It's very ductile and malleable. You can draw it into the finest wire, or form it into all kinds of shapes either by hammering or casting.
3. It's a great electrical conductor, so combined with attributes 1 and 2 above it's valuable for use in electronics, etc.
4. It works well for implants ,etc. and is usually well tolerated by living tissue ...so again considering attributes 1 and 2 above, it is about the best thing for fillings, crowns, etc. in dental work. It's a bit old-fashioned and demands a high level of craftsmanship but it's still the "gold standard" if you can find a dentist who still has the skills.
5. If all else fails, it is fairly soft and denser than lead, so you could use it for
bullets if you re-load your own shells. If lead kills ordinary things, and silver is good for werewolves and possibly certain other supernaturals, just think how great gold bullets would be! And they would certainly cut down on unecessary shootings. Like whose gonna waste gold bullets?
So after the basics (food, tools, medical supplies, weapons, and toilet paper) gold sure beats most other currencies I can think of except...