I read somewhere that Tom Paris was originally going to be Nick Lacarno, the cadet from The First Duty, played by the same actor. And that they changed that because they thought the audience wouldn't forgive Nick for what he did.
Would the character have been better had he been Nick Lacarno instead of Tom Paris?
First off I doubt anyone would have hated Nick Lacarno based on that episode. Half the crew was Maquis and Seven was a borg, and Seven briefly increased the show's ratings. And Nick Lacarno was a kid, everybody makes dumb mistakes when they're in college, if anything they would have identified more with him than a guy who'd committed vague unknown crimes in the past.
I think the character might have been stronger if he'd been Nick Lacarno.