It’s a solution that allows two parties, who are so paranoid they don’t trust banks, let alone one another, to send funds and maintain a record of transactions with one another.
No, it requires a lot more than two parties, because the resulting “funds” from the transaction still have to be valued by everyone else that provide goods and services. So it becomes a social issue if it is to be a currency, and then you just end up re-discovering all the lessons that lead to how currencies already work.
The valuation of Bitcoin is a completely separate topic than practical use cases of blockchain.
Incorrect. The transaction is not practically useful unless the currency has real value.