So if Kyle was black

He would be found guilty. End of story.

People's reactions would be the same. Because self defence is self defence regardless of what race you are.

There would be no reactions at all, because the media would not have cared and no one would have ever known about it, and there likely wouldn't even have been a trial.

What if racist Dummycrats STOPPED making literally everything about race and Identity Politics?

The Media's reaction would be to look the other way, as if it didn't happen. So for the most part (Other than Fox News), the story would be largely ignored. Black-on-Black, and Black-on-White crime isn't newsworthy.

The Liberal Left-leaning media would have you believe that a black with a gun is akin to a vegetarian with a hamburger.

This story was only newsworthy because it occurred at a BLM rally, so the victims, while not black, were at least black-sympathizers. So the media could attempt to portray Rittenhouse as a White Supremist, and thus further fuel the racial divide in this country. Their reason for existence.

He isn't black and so is a meaningless race baiting question

If all else was equal except for Kyle's race, we would've never heard of it. He would've never been charged, it would've been ruled a justified defensive shooting. Except for the fact that the deceased were participants at a BLM riot, it might've been politicized by the left regardless.

Depends, if the people who tried to kill him were Trump supporters then he would be hailed as a hero

If everything else were exactly the same he would still be a "white supremacist"