I mean US is the one which gives arms to SA. US also destroyed Syria, Libya, Iraq, Afghanistan, Somalia and so on. No one’s hands are pure when it comes to the military industrial complex.

This is the typical "no one is perfect, so beeing bad is also fine" - argument (which I personally disagree)

Not really. Unless you propose that he completely stops doing business with everyone, shuts down spacex and Tesla etc, not sure what’s your point. SA, a major energy country, having a stake in Tesla is a pretty remote thing as compared to their prince having a stake in a speech platform.