SeaShells, just asked a couple of friends / contacts. This best answer:
"we are from Durban and went back in april/may for a visit. Durban itself isn't wonderful, but Umhlanga, ballito and salt rock are all within driving distance of the new airport and are lovely. There is lots to see and do, incl the beach, which of course is stunning as it's the warm Indian ocean. Let me know if you want any more info."
It seems that the general consensus is that Durban is ok, if nothing else. However, 30 minutes outside and you've got amazing areas. Ballito and Umhlanga Rocks are nicest - it's just north of Durban.
Umhlanga official tourism
(random search, so no recommendation) of Umhlanga based travel agency. Give you an idea of the kind of day trips you could do from there: Day tours from Umhlanga
Ballito accom
Ballito attractions
General info on KwaZula Natal north coast
In summary, if you could get it a lot cheaper, I'd go for it, definitely. As long as you use common sense (well, for Africa), it's safe. We've been burgled twice in London, never in SA, for example. Don't drive woman alone at night if you can avoid it, always keep car doors etc locked (no-one has ever tried opening my door, but it's so ingrained I do it anyway), don't flash your cash, cameras etc. Same really as for any country where poverty common. Not that it's an excuse, obviously, but a reality unfortunately in SA's case.
As far as whether doable alone without dh, well, I wouldn't, but it's because I'm a complete whimp. More about practicalities of 2 under 5 really. If you could have a week or so after dh's conference, I'd go for it if I were you. Most beautiful sandy beaches, fantastic weather, nature reserves, culture. Flight cost would be the deciding factor for me. Shout if you need more info.