Regarding Geoff’s point 1 and 6, instead of giving the money to local authority staff could the quid be given to the poorest people in society on top of any benefits already given to them?
I imagine that, initially at least, the people willing to provide services in exchange for quids will probably be people already in despearate need of extra liquidity (such as the unemployed). This would further mitigate the issues raised in points 1 and 6 above.