Studying /Moving - Brasil - Pretória (Pretoria)

Hello everybody,

I am Brazilian and dating a native of South Africa in Pretoria resident . In four months I will go to Pretoria to study English at a university . I install myself definitely plans in the country. For this reason I registered on this site for more information about life in South Africa .
** How does the issue of work to foreigners? That I was studying I have some advantage ? Do I need any special visa to work? In this condition can be more than 3 months in the country?
** The marriage to a native gives me rights similar to natives?
** In other research found that many South African companies hire professionals who speak Portuguese , due to business in Angola , Mozambique and Brazil . There are many difficulties in finding employment in these conditions ?
** Is there a community of Brazilian expatriates in Pretoria ?

There are many questions , I would be very grateful if someone can help me