This smacks of circular reasoning - for a correlation to be demonstrated, you'd have to know that "there is a meaningful way to categorize human beings into races " to start with. So, this too needs a citation.

Well, there have been such categorisations in the past. Consider, for example, Apartheid - the entire legal system enshrined under that name depended on a categorisation along racial lines. However, it was far from a perfect classification; to quote from the linked section of the article:

The Apartheid bureaucracy devised complex (and often arbitrary) criteria at the time that the Population Registration Act was implemented to determine who was Coloured. ... Different members of the same family found themselves in different race groups.

(What was then done with that classification was racism in an extremely negative sense, a very conscious and institutionalised form of racism-3; however, the point of the citation is merely that there were laws laid down that served as a racial categorisation, however flawed).

There is a largish argumentative gap from "some genes confer a desirable resilience to sunburn" (possibly conferring some less desirable traits at the same time) to "some races enjoy unalloyed advantages over others by virtue of heredity".

Oh yes. Agreed. One very minor desirable feature does not make an unalloyed advantage, especially when paired with an unknown number of other traits, which may be positive or negative.