re: South Africa seizing land from white people

Maybe. The local benefits of colonialism were uneven, often on purpose, with the aim to keep rival populations at each other's throats so as to mitigate blowback against colonial officials. That policy might have been useful in the short-term, but the long term effects of it have outweighed any benefits of the colonial system.

The Chinese are entering into a much different situation, as they are dealing with modern nation-states. Firstly the Chinese are focusing investment on long-term infrastructure projects while avoiding what it terms as neoliberal policies focused on privatization and short-term gain. Given the infrastructure issues in these countries, and the inability of governments there (and even in Western countries) to pay for these projects generally, this is a good way of gaining goodwill in these countries, provided these projects are completed. Secondly, the Chinese are interested in developing their own sphere of influence which can assure them access to raw materials while at the same time provide for access for developing markets, which was the same impetus for colonialism, but without direct interference with social institutions. At this point, they've invested around 4 trillion or so in projects around Africa and Asia, and the bottom floor of that investment is projected to be around 8 trillion. Their entrance into local politics has been minimal, and they tend to want governments to favor stability above all else.

Given the unmitigated disaster that was the Late British and French colonial systems, the effects of which we are seeing today, the Chinese seem hesitant to offer much more than investment opportunities at this point. The Chinese had their own unique colonized experience, and one of the explicit purposes of the CCP during the Mao years was to focus on development so that there would be no possibility of being dominated again. What that means for interactions with the post-colonial world at large remains to be seen.