Pentaxuser echos my sentiments about travel along the coast from Cape Town to Port Elizabeth and Durban, and my experience there is similarly stale dated.
I worked in Cape Town and Sutherland from 2002-2005. Before I arrived in Cape Town, I'd heard many horror stories about high crime levels, but never experienced any crime personally, nor did I witness any. Possibly because I was cautious: never travelled alone at night, didn't travel to troubled urban or semi-urban neighborhoods. Situational awareness is paramount.
Some suggestions:
Street photography options in the Western Cape - you should be spoiled for choice. But with only a week to look around, you have the tourist's dilemma: see a lot of places a little, or a few places more thoroughly. Cape Town proper, Kirstenbosch National Botanical Garden, all around Table Mountain, Cape Point, the wine country ... the list of worthy sites goes on and on around the Cape. Never mind farther afield from Cape Town.
If you have botanical interests, the Western Cape is it's own floristic kingdom, quite diffent from the UK.
Mossel Bay (east of Cape Town) is picturesque, and a prime whale watching site from June to November (as is the drive along the coast (not just the N2 highway) from Cape Town to Mossel Bay). De Hoop and Wilderness National Parks are along the coast route.
If you like desert landscapes, the Karoo desert (unique flora and fauna) is on the inland plateau. From Mossel Bay, the Karoo National Park, near Beaufort West, is a few hours away.
PM me if you'd like to hear more.
cheers
Tom