Q. Should I attempt to recover small debts?

A. In all cases you should try to recover whatever money is outstanding to you.  If it becomes obvious that the debtor has no funds available then you would be wasting your time to take the matter further as all you would incur is further costs with little or no prospect of payment.

Q. Where debts are on-sold can the purchasers of these still pursue these for instalments owed to others?

A. Yes.