Using the Merriam-Webster definition of racism,
racism
1 : a belief that race is the primary determinant of human traits and capacities and that racial differences produce an inherent superiority of a particular race
You CAN be racist against white people but is it OK?
Is it OK to tell an entire race they need to atone for the actions of their ancestors?
Is it OK to tell an entire race they are racist simply because of their race?
Is it OK to blame an entire race on the actions of 2 people?
Is it OK to purposely tell your kids to not trust an entire race?
Sadly I doubt I'll get many honest answers because it's not PC to you think racism is OK as long as those your racist against are white. But hope springs eternal.
IMHO, it's not ok to be racist against anyone. The Establishment in the US has already tried reverse racism (I just made that up, cool eh?), they called it Affirmative Action. Any time race is a factor in any situation, even with the "best of intentions" it's still racism and it's not ok. That's my more general answer to your specific questions.