It’s useful in electronics for creating fine wires and IIRC heat dissipation.
I recall a sci fi story where a means of extracting huge amounts of gold cheaply was discovered, with the end result that the #1 use of gold became the lining of sewage pipes, since it’s so corrosion resistant.
You could alloy it with another metal to make it slightly harder. The good industrial qualities of gold are that it is highly conductive and has very low corrosion. It is probably the ideal connector for electrical interfaces for that reason.
Gold would be a superior replacement for copper in plumbing and many construction applications, and quite a decent second best for wiring. Because gold has such corrosion resistance it would be a great roofing material. It might replace steel for many construction purposes such as bridges, if it were cheap enough to use more of it, because of its long lifetime exposed to the weather. It would make nice pots and pans. There are lots of things it would be great for.
You could buy a private army to defend it. Hell, a private air force and marines too.
The gold’s hundreds of feet below the surface. How can the gold rushers wage war and mine it at the same time?
Very slowly. Slowly digging their way in, gunfights erupting whenever two mineshafts meet…sort of multiplayer competitive Minecraft with guns. 
I think a dwarf faced with the sight of a cube of gold 575 feet on a side would stand there staring catatonically, drool dripping down their beard, possibly dying of thirst before snapping out of it. 