The origins of debt are ultimately material. Alice has a bushel of apples today, but Bob won't have a bushel of oranges until next month. The function of money is to decouple the general function of debt from its material details. In other words, you can have debt without money, but you cannot have money without an underlying debt.
Not a chance. I believe we're all mostly out here trying our best to make the numbers add up, when we're not (judiciously, I hope) looking the other way because some particular numbers offend our sensibilities. People are complicated, and economies are made of people. Money isn't a law of the universe, it's a technology we invented and (mis)apply in accordance with our values and desires.
It can be in barter clubs and with demurrage currencies. The problem with debt is that it takes two to pay off debt. The creditor has to spend off their savings at the same rate the debtor pays off their debt.
This type of synchronization requires a negative price signal on money though.
Money is money from the future. If I give you one dollar today, you value it not because you can instantaneously exchange it for a soda, but because you can exchange it for a soda tomorrow.
That is not how debt works, not even in a 100% reserve system.
You are never borrowing from the future. In a 100% reserve system you borrow from other people in the present. If you fail to repay you don't disappoint your future self, you disappoint another person in the present.
In a fractional reserve system loans create both debt and new money and the debt is always an obligation to pay back present money on a fixed schedule.
