(1) that is the precise definition of opportunity cost. It is everything you forgo the opportunity to do whenever you choose to do anything. Whether you are choosing how to spend your money, or spend your time, or devote your attention, or expend your energy. All of those are opportunity cost decision. It also includes everything you forgo for any given decision. If you choose to buy a Ford, perhaps the opportunity cost could be that you don’t buy a Chrysler. But it could also be that you don’t eat out as often, because you have to make car payments, or that you don’t buy a PlayStation. It is all of those things. This is the definition used in the field of economics.

(2) raising prices will always reduce demand, outside of the very specific circumstances where demand is inelastic. Supply and demand is an inescapable law of economics, and subverting it will always result in failures in the supply chain. The scenario you described will also not increase hoarding, it will most certainly decrease it (whether arbitrage trading crops up is a different issue, but one that is completely unrelated to hoarding).

(3) I used the term rationing authority because it was a neutral descriptor. Anybody who acts as an authority on allocation rations is going to be creating the same inefficiencies (though you’d expect the parts of the supply chain closest to the consumers to be the least inefficient)

Most of what you’ve said has demonstrated serious misunderstandings of how the basic principles like supply and demand and opportunity cost works. Your argument that raising prices increases demand should really just be dismissed off the bat.