Precious metal, if held in physical form, has the unique property of being no-one's obligation. Additionally, it is by definition a bearer "instrument" and easily transportable, therefore suitable for mitigating political risk. This is why it performs well in times of crisis.
There is no one-size-fits-all answer to your second and further questions. Too much depends on individual circumstances, risk appetite and time horizon.
Your ending hints at my problem with inflation discussion and I suppose economic projections and asset price projections in general based on some macroeconomic fact.
One would assume based on the casual and confident nature in which people talk about them, that rising inflation should result in X. But if being honest they will also include "ignoring second order effects", which can mitigate or completely reverse the expected outcome. The complexity is monumental.
I believe one could say rising interest rates should reduce the value of existing fixed rate bonds denominated in the same currency. Im not sure a lot else can be said, with confidence. Much else is paradox.
There is no one-size-fits-all answer to your second and further questions. Too much depends on individual circumstances, risk appetite and time horizon.