Money circulation

With the big March against cuts last Saturday in London, I have been looking at people's arguments against cuts. It's surprising how there's a blind spot about jobs. Yes, we need to address human need, and the cuts are making that harder to do (at least that's what's argued), but people also argue that if you cut jobs, you lose tax income. The thing is that jobs in the public sector are funded out of tax income, so some of the tax spent providing public services comes back as tax paid by employees, in a weird cash back scheme. But never mind, because this all creates jobs for people to administer the tax, and most crucially of all keeps the money moving. It must not sit still because if it did we would see how fundamentally useless it is.

If all money magically disappeared, would we reinvent it, or we would we look at what we have to sustain us and work out how we can most efficiently use it (ie with the least amount of human effort)?