I think the general thrust of this gentle exchange is that Trek is fantasy more than science fiction. Like Avatar.
Right. There are many completely fantastic elements in the premise of Star Trek
that must be accepted without reason to believe in them, in order to suspend disbelief.
How I prefer to define the science version versus fantasy argument is I consider something science fiction if it uses science and/or pseudoscience to justify its improbable or impossible elements.
Fantasy, on the other hand, while it might
have scientific or use of pseudoscientific elements, will usually have elements that abandon any pretense of a scientific rationale.
Avatar falls into the latter category; even its invoking of a Gaia-like mother earth goddess is couched in pseudoscientific ideas. So does Star Trek, as even some of its most ridiculous conceits - like meeting the Greek god Apollo - are waved away with the idea that beings that thrive on worship apparently evolved organically somewhere, somehow, for some reason. Off the top of my head, the TAS episode "The Magicks of Megas-Tu" is Star Trek at its most fantastic given this description, as it's an episode where they enter a reality where magic actually works for some reason.