No, I'm not for 'forced interbreeding'.
The provincial fights of the Old World (one country mad about another country about something that happened 500 years ago) don't happen here because Americans are now a Heinz 57. Most of us have a taste of multiple European bloodlines. The same will happen with the Races. Asians and Latinos marrying 'whites' is pretty common and accepted. At some point 'blacks' and 'whites' marrying will be just as common. Course, CFM and Guno will still shit their pants and have coronaries, but ... who cares.
I see where you're coming from, but the variance between European cultures and appearances is far less pronounced than the variance between Europeans and people of other parts of the world.
The greater the variance is in these aspects, the harder it is to move beyond certain biases.
Also, some traits are more genetically dominant than others. Even if all groups equally interbred with each other, some traits would eventually disappear. Granted, there are those who realize this genetic disparity and, perhaps, seek to gain from it.