Episode itself was kind of blech, but I have to disagree. I think Worf was the perfect character for that encounter with Troi.
Hear me out. It's already been brought up that Klingons are generally about violent, and that I'm equally violent ancestor is only natural. This is true, but it's only part of it. One should also take a closer look at Worf as a character. In some ways, he is the most disciplined and stoic member of the crew. He avoids pursuing any form of romance or flirtation with other crew members for a large chunk of the series (explaining to Guinan that he considers human women too 'fragile,') and his honor and code of conduct is the most important aspect of his life. His discipline is key to his entire personality, and if you ever saw that DS9 episode where Dax drags him off to Risa, it actually retroactively explains a great deal of that. But compared to Riker, even Picard or Crusher, he is far more restrained, and far more concerned with what is right and honorable.
If you were trying to create a disconnect between how the character normally behaved, and how he was behaving at during the 'transformation,' Worf was the PERFECT character for that. The only one better suited would have been Data, but fortunately their science didn't get so soft as to try that shit again.
For Worf to even attempt to impose himself on Troi, that was all manner of shocking, not because it was a black man assaulting a white girl, but because it was freaking WORF. To see our honorable, stalwart Klingon behaving in such a manner was disturbing in a way far more profound and poignant because of who he was, NOT what he looked like.
They didn't decide to stick the black guy into the rape encounter, they decided to stick the character who was the most sexually repressed and behaviourally conscious into the rape encounter.
And that's part of what the success of the series as a progressive force for racial equality has been. Racial equality isn't just about walking on eggshells, trying not to say something that someone could somehow interpret as biased. Equality is looking at the traits of a character, looking at what you want to have happen, whether it's an action that fits the character, or deliberately runs contrary to their usual pattern of behavior to suggest something is amiss, and asking yourself 'does this work?' To which character an action is assigned should be based upon the traits of that character versus the effect being sought, and NEVER be based upon the color of their skin. The brief scene with Troi was intended to be shocking and discomforting, yes, but not because it was a black man assaulting the poor white girl, but because the action is one that Worf, as a CHARACTER, would never have attempted under normal circumstances.
Now you could argue that it still shows a black man assaulting a white girl, but if the suggestion here is that the scene should have been modified, that Worf should have been removed from that role solely because of the color of his skin, then congratulations, you're doing exactly what you are accusing the source material of doing. You are looking at a narrative, and trying to assign actions and roles using race and skin colour as a measuring stick. Sure, you might tell yourself that you're trying to portray said race in a positive light, but the fact remains that you are still allowing it to cloud your judgment, and slant your material.
The show has definitely had its stumbles. Again, that tribal episode, and that godforsaken episode about the colony full of Irishmen, you'd have better luck trying to leverage accusations about those. But for the episode you're focusing on, frankly, all I see are writers taking the characters, and assigning them whatever roles best serve the purpose of the narrative, and THAT is true equality. Anything short of that, trying to substitute for a whiter character in the antagonist position 'just because racism', just does the very thing we are trying to avoid, by saying 'we should treat this black character differently than we would if he was white.'