Regarding Bell Hammer Gold and Bell Hammer Metal Grease, is it possible to mix the two? I would like to know if it is possible to adjust the viscosity and if mixing the gold with the metal grease will make it more metal-like in nature.

It is no problem to mix LS Bell Hammer Gold undiluted with metal grease.
The properties of the two products are completely different approaches, so you can synergistically bring out the best in both products.
LS Bell Hammer Gold changes the composition of the metal. The metal grease is for individual lubrication such as preventing rodding and seizure.