If I was your age, yes I would go work in Christchurch. When I was your age I did work in Christchurch, at the Christchurch Press actually.
There are great opportunities down there and you obviously have the skills to be able to assist in the rebuild. The climate is good, the people lovely. The bars are still operating out in the suburbs, the majority of the malls are open. There are still things to do at the weekends and you are really handy to the ski fields and the country. You have to remember that what you see and hear on tv is mostly the negative side of things.
You could always jump on a flight and go have a look. You can get flights for less than $120 return most days.
Even with all the damage in certain areas a good sizeable chunk of Christchurch is either undamaged or the damage is insignificant. If you look at geonet you will see the ground still does shake, but if you go back pre earthquakes and look, you will notice that it always did.
Most of the shakes can't even be felt.