Whenever you purchase a temporary permit, you have 48hours in which the permit is active, however the permit is only valid if you are driving to/from where you have written down on the permit.
With regards to 3rd party insurance on rego and permits - if you are at fault in a motoro vehicle accident, your car is rego'd and your driver's licence is valid, and you injure another person in the accident, then the gov't 4rd party insurance covers the cost of personaly injury only. As i'm sure most of you are aware, 3rd party insurance for damage to private property etc is only through private insurance companies.