This system doesn’t need to be implemented as a Cryptocurrency. Just a normal database would achieve the same effect without needing to pay miners.
Another problem here is that the admin would need to store the cash locally because if he were to store it in the bank he may or may not get back the same bill unless a safe deposit box is used.
Even if all the bills are recorded online there is a high risk of robbery. People are smart, they’ll work around any limitation if there were money to be made.
Lastly, this is not a trustless system. People have to have trust in you and your team. What’s stopping you and your team from engaging in fractional reserve banking after you’ve recorded the bills? What happens if your company go out of business? From whom do user recover their money if you and your team were to disappear?
So, we would offer any way of sending in your USD, but it has to end up in bills.
If they send us bills, it's like a 10 cent stamp, that's the cost it takes to get that money to us.
if you send in USDT, we would have to transfer it to BTC, sell it on coinbase, go to the bank our selves to get the bills, and that's really not as easy.
But the whole point in doing any of this is so that we can build a database of the money we have received, so that we can give proof of stake coin rewards to those people, kinda like a Basic Income, but as I understand it PoS doesn't last forever and we might have to implement another system toward the end to make this a basic income coin, for now though until it just runs out and reaches it's max cap, 2.5% is what a staker will get, and the 97.50% of the rest of what that staker would have got ends up going to all the people who sent in money, distributed smartly based on what they donated, you can't just set up a database to do this with some other coin, you need control over the amount staked, the whole cryptocurrency has to function in this way.
A security deposit box would work, I did mention that earlier however.
With every ICO you have to send them money to receive coin, this would be the same thing except perhaps longer, until all the coins are distributed.
There is a high risk of robbery for many things which are already out there in the crpyto world, and that doesn't stop people from making those things.
The bills wouldn't be released, they would just be kept, the whole point is that people can take their bills back at any given moment.