I think FIAT is too big to be removed for at least 100 years. Anything is possible in the future though!
"At least 100 years"? How cute.. FIAT as we know it will probably be gone within the next 15 years. Economic collapse is imminent and that will change our monetary system for a long while, perhaps forever.
As you've stated anything is possible in the future and what I just wrote could very well be proven wrong and the complete opposite could happen. Time is the only thing that is certain in this world.
I doubt so. Like I explained in my post just above yours, since the beggining of the times monetary power was tied with ruling power, and that will never change !