Your claim of history is really quiet short sighted. When the BRITISH were invading and colonizing South Africa and Zimbabwe, the Germans were committing genocide in Namibia against local populations, and the Belgians were doing the same in the Congo, so it is true people were fleeing these nations for opportunities to not get murdered. Doesn't make the British genocides any better. The British were happy to have a desperate labor class come into a country where locals refused to work on their own stolen property. I would not work as a slave in my own house to an invader either. The entire claim is perverse really. The British destroy Malawi and Zambia and Kenya worse than Zimbabwe and force people out of one nation into another and you claim people moved willingly? That's like saying jews who ran away to Russia and the middle east in WW2, deserve anti-semitism because they chose to leave central Europe.
Not really. The exports were smaller under both apartheid regimes as were the economies. What was true though was you had a highly exploitative system, which permitted whites in these nations to be among the richest white populations on the planet, because they had a large group of low wage labor slaves, doing work who they got to profit off. South Africa is quiet developed, and Zimbabwe did quiet well under Mugabe until Anglo sanctions in the late1990s.