First, Ayn Rand was no 'Libertarian Superstar'. She didn't like them and they didn't care much for her.

I've read the complete text of her speech and the Q&A, and can't find any defense by AR of genocide. She does defend the colonization of the US and the establishment of a country of the mind, of individual rights and freedoms, and technological progress. And she didn't support the concept of affording the indians individual rights that they didn't support or recognize themselves.

Salon is just not a very reputable source of information about AR, her thoughts, and her philosophy.

For one, there should have been an ellipsis (...) at the end of the quote, she continues on...

If you study reliable history, and not liberal, racist newspapers, racism didn’t exist in this country until the liberals brought it up—racism in the sense of self-consciousness and separation about races. Yes, slavery existed as a very evil institution, and there certainly was prejudice against some minorities, including the Negroes after they were liberated. But those prejudices were dying out under the pressure of free economics, because racism, in the prejudicial sense, doesn’t pay. Then, if anyone wants to be a racist, he suffers, the workings of the system is against him.

Her views on the taming of America were prevalent at the time westerners colonized North America. Not politically correct today, but that was the justification given for "Manifest Destiny", that the continent was going to waste and needed civilized. I guess Rand didn't buy into "white guilt" either.

I think the rest of her comments will stand up to modern scrutiny. Her argument that racism isn't profitable speaks for itself.

I think she's being hyperbolic in saying "self-consciousness and separation about races" did not exist until some recent political movement. People have had in-group favoritism since prehistoric times. I think she's rightly saying accepting the premise of identity-group politics is a mistake. She makes it sound like a recent development, but it's actually more like the ancient urges to hit or steal.

"Cultural genocide" means what? Mayan culture of human sacrifice was abolished. Does this constitute cultural genocide? No. Nazi culture was to commit genocide, does killing Nazis constitute cultural genocide? No.
Genocide is the purposeful murder of people pursuant to and because of their race, ethnicity, color, etc. There is a right to life, not a right to culture. A certain culture may well have been present when Americans built a country based on individual rights, but this does not mean Anglo-Saxon culture is responsible for its widespread acceptance in the West, or that the culture precedes it hierarchically. Fish and chips is delicious, but it has nothing to do with a proper body politic. Culture-centric views are not concerned with principle, but rather looting. Culture-centric views consider any given aspect of a culture as equal to any other and shows a total disregard for how values are dependent on each other hierarchically.