Roddenberry may have wanted to avoid some of the more obvious mistakes of the day but he wasn`t scientifically literate in any way, shape or form. Warp drive and the transporter being two obvious examples.
Which is why he consulted with people who
were scientifically literate. That was Roddenberry's strength: calling on people who knew more about his subject than he did. He consulted extensively with all sorts of scientific advisors, and he hired a lot of genuine SF writers to contribute to the show. True, he freely took poetic license with the technical advice he was given, and he didn't always apply it correctly, but he was the first SFTV producer to even
try for accuracy to any degree at all. Whatever you may feel about the results, it is provably false to claim that the intention was to make a fantasy show.
And warp drive is hardly fantasy. It's grounded in the equations of the General Theory of Relativity, and there's a lot of hard science backing it up as a theoretical possibility, even if it's probably unattainable in practical terms. Hell, it's impressive that Roddenberry even acknowledged that there is such a thing as a speed-of-light limit that requires a form of space-warping technology to achieve interstellar travel. Most SFTV before ST, and a lot of it afterward, just ignored that and assumed you could get to other star systems via conventional rockets. (The original
Battlestar Galactica was horrible about this, claiming that the fleet's maximum velocity was lightspeed and that it almost always travelled below that, while still having it reach a different star system virtually every week and pass through multiple so-called galaxies.)
As for transporters, those are more of a stretch, but teleportation was an accepted premise in science fiction literature long before Roddenberry adopted it, and at least the concept is grounded in some genuine scientific concepts such as matter-energy equivalence and atomic theory. It's not "fantasy" to portray improbable technologies or to take poetic license with real science. Teleportation has been a staple of a number of well-regarded works of science fiction such as
The Stars My Destination and a couple of Larry Niven's universes.
That's what Roddenberry did. No, he wasn't a science fiction innovator, but he was an effective SF popularizer. He brought together writers and consultants who knew their stuff and built an SFTV universe that synthesized and distilled a lot of concepts that were well-established in literary science fiction. Science fiction, not fantasy. Maybe most of the authors he hired (Matheson, Sturgeon, Ellison, Spinrad, etc.) were known more for "soft" science fiction than the hard, technical stuff, but confusing soft SF with fantasy is highly erroneous.
In the first pilot we have telepathy and mental illusions. Hardly grounded in reality.
Well, not grounded in reality
if you dismiss telepathy as feasible or possible, but many scientists of the day were (and are) studying the phenomenon. Police
still use people with supposed ESP to assist in crime-solving.
Which proves nothing except the gullibility of certain police departments. Most "scientific" studies seeming to support psi powers actually have deeply flawed methodologies, and when well-designed, fraud-proof tests are proposed, psychics seem reluctant to participate. And the success rate of police psychic consultants is no better than chance.
Still, you're right that there have been some who've believed that psi powers might have some legitimate basis behind them. Telepathy has long been an accepted premise within science fiction, and a very common one, which is why Roddenberry made it part of ST, his distillation of common prose-SF concepts and themes. At least, it was a more respectable SF conceit back in the '50s and '60s than I think it is today.
Second pilot we have much the same except the mental powers are because of a swirly pink thing at the edge of the galaxy that turned peoples eyes silver and their hair gray.
And scientists of the day were speculating whether our galaxy had an defined "edge" to it, or if it just petered out. And what such a barrier might do to human evolution.
Err, no, they were doing nothing of the sort. Even if there were such questions about an edge to the galaxy (which is something I've never heard suggested in all my years reading about astronomy), how do you get from "edge" to "barrier," and what could it possibly have to do with human evolution?