A lot of pseudo-science dressed up as sexual kink...
If I may, I'd like to address a number of the points that you brought up in your post:
1) Blacks are no more "alpha", or "beta", for that matter, than Whites, Asians, Latinos, Eskimos, or your average cigar store Indian. People are Type A or Type B personalities based on a mixture of genetics and environment, the old Nature vs. Nurture argument in Psychology. For every piece of "evidence" that the Black Superiority crowd on this website cites as evidence of "Black Superiority" (penis size as just one example) there is anecdotal and empirical evidence that refutes those assertions.
2) If Whites are hard-wired for self destruction as you theorize, since all human beings descend from a common ancestor, wouldn't all races be hard-wired for that? As for wanting to reduce "prior dominance", for that to be true, an overwhelming majority of whites would have to actually be of that mindset, which as I have experienced only a small minority of white people, usually the hand-wringing liberal types who suffer from white guilt, feel that way. The average white person, I believe, wants nothing more than what every other person wants- to live their life in good health, and to be successful.
3) White people, at some point given declining birth rates among whites and increasing birth or steady birth rates among Latinos and Blacks, will go from majority to plurality. For mixed race individuals to make up a majority of live births would be to suppose that a majority of people are procreating outside their racial group, and the data, no matter how much anybody on this website wants to believe it or thinks it's true, simply isn't.
4) Homosexuals, depending on whose data you believe, represent from as little as 2% to 10% of the population, across all races, not just white. As far as I know, that refers to the United States, so I won't make assumptions about the world population, but I would image the numbers are similar.