Locarno was a guest star central to a TNG story marking a shift in a main character. Changing his characterization (as sketched out by Boothby) would be tantamount to retooling, in which case it’s just as well they went with Tom Paris. It’s not like avoiding this loose end of backstory-plus-casting is more important than staying true to character continuity.
I wouldn't think that would matter. Plagiarism is plagiarism, regardless of how different the story or character becomes after the initial starting point. But even if there are royalties, I would think that they would only last a certain amount of time. In my audiobook work, if I get paid by royalty share, it only lasts 7 years.
Sure, but should it result in permanent residuals for creating a character or would the similar backstory element be resolved differently, perhaps with a one-time settlement?
Beats me. All I was pointing out was that if the VOY writers couldn't use Nick Locarno because of a royalty issue but could use a character with a different name but 99% similar backstory and played by the same actor, then why didn't the writer of TFD automatically sue for plagiarism.