Ok there are bad news. Your theory makes a lot of sense when we just evaluate input and output of a dragons den. The problem is that gold is atomically more stable (Au: B/A=7.936 MeV) than carbon (C: B/A=7.468 MeV). That means that you have to explain a huge amount of energy this process consumes. This is alongside the energy that the dragon uses to live and even wastes in the whole fire spitting situation.
Ok there are bad news. Your theory makes a lot of sense when we just evaluate input and output of a dragons den. The problem is that gold is atomically more stable (Au: B/A=7.936 MeV) than carbon (C: B/A=7.468 MeV). That means that you have to explain a huge amount of energy this process consumes. This is alongside the energy that the dragon uses to live and even wastes in the whole fire spitting situation.
When you eat herds of cows you get enough energy to fuse gold.
Fusing your waste to gold has the evolutionary advantage of not causing any pollution around your home.
The fire spitting isn’t a waste, the dragon (s)melts and eats rock to create/enlarge its lair. Not sure how those minerals affect your chemistry.
Their GI tract is very slow and live live a very long time. They shit like a parking meter, a nickel an hour.