I've heard that argument, but I can't really co-sign it. First of all, as individuals and as a group we have more power than we know or exert. But most of all, I've seen black folks insult whites, Asian and Latinos with racial slurs with no good reason behind it other than they are stupid assholes. Sometimes to their face, sometimes behind their backs, but it's nasty and it's wrong.
Like I said, there is a difference between a racist act and a prejudiced one. As I said in my previous post, African Americans can be prejudiced individuals and have said many of the things you mentioned. However, as a collective group, African Americans do not have the institutional means/power to control the life chances of an entire group of people based on their prejudiced attitudes or even beliefs. That is a huge mistake people make, trying to equate the two when they are different entities. Racism and prejudice are not mutually exclusive but they are most definitely not the same. Any "ism," in society is based on power. It in no way demeans African Americans to note the historical and contemporary obvious. It is an unfortunate fact of life that we all still must deal with. Some whites like to use the same examples as the ones you used to "prove" that African Americans are racist to somehow absolve their own racism or to put us on par with them. That is a fallacy too many African Americans have fallen into for a host of reasons.
Tell you what, put all those African Americans together who've said nasty things against whites and have them attempt to impact the social, economic, political, educational lives of whites and see how far they get.
Now do the same for whites and see the difference. Oh, you don't have to because it exists in every institution that directly and indirectly promote "whiteness" over everything else.