I enjoyed Worf in DS9. When was he racist against groups other than Romulans?
I also disagree with the criticism of the Children of Time Klingons. They didn't contribute nothing, they provided a lot of people direction and meaning. And they provided for themselves so they weren't using any of the main group's resources either.
But what I like best about the way they used Worf in DS9 is the way they contrasted Worf's version of honor with the reality of the Klingon Empire, showing that nobody really lived up to the standards he had always taken pride in.
I agree there are some episodes that made him appear childish, like Sword of Kahless and Hippocratic Oath, and those episodes I could do without.