Great post. Being a native Capetonian myself I am curious to know if you explored the rest of the Cape, because you basically just mentioned Loop Street and the VA Waterfront ( biggest tourist traps ). One can really appreciate the breathtaking beauty of the region by taking day trips around the peninsula and the wine region.
The accent you referred to is really a dialect - mixture between Afrikaans an English - with mixed race Capetonians having the strongest accents. The other language is most likely Xhosa. After English, the most widely spoken of the 11 official languages in SA. Looking forward to the rest of your trip report.
Cheers.