Do we need to rewire our house after a major power surge?
Your local, on site electrician will best assess this, but in all likelihood, yes, you need to replace all the wiring (and your insurance company or the utility company should be footing the bill - your insurance company will probably turn around and get the money from the utility company, it's truly their fault.)

Why? When you have had an overvoltage condition of such magnitude that: 


  It caught the breaker panel on fire, some outlets, switches and light socket on fire too.


The problem is not resolved when the overvoltage goes away and the fire is put out, because every place that arced now has a lovely "carbon track" where it's supposed to have insulation - and carbon is a conductor - a lousy one, but plenty to cause problems. Once a carbon track forms, it's very easy to have repeated arcs at much lower voltages.

Typical household wiring is 600V insulation - yours was exposed to likely 1100-2400V depending on the local system.

In addition, you may well have damage at places you cannot see inside the walls. You're lucky the house did not burn down.

So - not only the wiring, but also the receptacles, switches, and pretty much everything that was connected to them is now highly suspect and should be replaced.