All of what you're saying sounds nice, but everyone who isn't completley delusional knows that importing a bunch of hatians into your neighborhood will make it shittier. Half your neighbors becoming hatians results in your neighborhood looking more like Haiti. They have an average IQ of around 70, which means a lot of them aren't even fit to stand trial. There is no scenario where the mass importing of these people results in anything but a filthier and more violent place. I don't say that to be mean, I say that because it's exactly what will happen.
It sounds like you're aware there are group differences but think we should ignore it.
Here's a good article about some of the detriments that arise with racial diversity. I don't think these divisions are easily replicated in a homogeneous population.