Sounds good to me.
It is a decent salary that you have been offered to stay in South Africa and especially in Durban!
The central and 'tourist' areas of Durban are fairly safe and violent crime is rare. The main problem there is petty crime such as pick pocketing. Use some big city precautions to counter it such as money belt attached to clothing, and taking out only as much cash as you can afford to lose.
Always catch a cab to and from nightspots. Parking is generally OK outside suburban restaurants, but use off-street parking overnight (most accommodation options offer this). Never leave valuables exposed on your car seats, even while driving.