Zimmerman verdict: Not Guilty.

[Tiberius]

Assuming that all the above are true,

How would one go about navigating the world as humanely as possible? Would there not be more of a preference towards one "race" (assuming the differences you provided)?

Easily...just treat all other humans the same way. There are differences between races, but there are differences between individuals as well. Every person, and every race has differences that make them inferior in a way, but also that make them superior in a way when compared to other individuals / races. For instance, Africans tend to be faster on average, and Asians smarter. The point is, no race is ultimately superior; we all have our advantages and disadvantages.

By the way I think the differences are very malleable in that if you took the Japanese man and he had kids who only knew white American culture and only did white American practices then they would slowly but surely eventually start to assimilate (genetically) through generation after generation.

Certainly, and that is how you get mixed race people. However it would likely take a while for the traits to become unnoticeable.