And of course OCs can die. Unlike Kirk etc etc....
Yeah, because the books would never be allowed to kill off a canonical character like Janeway or Shakaar or Mr. Homn or... hey, wait a minute...
Shakaar and Mr Homn are walk-ons at best.
Janeway is one I'll give you, but she's the exception to the rule. Characters from "dead" franchises are not as immune as "active" ones
If you're writing Kirk, or Spock, or McCoy and so on you know you can't kill, cripple or otherwise hurt them nor can you permanently marry them off, retire or otherwise make changes in their status quo.