Persis Khambatta would have been about 21 at the beginning of a TOS 4th season, so she could have played the newly assigned ensign Ilia, replacing the recently promoted assistant science officer Lt. Chekov as navigator. I was sad to learn that Ms. Khambatta passed away in 1998 at the age of 49.
Somehow I think a bald woman would have found acceptance a bit difficult in 1970, when everybody was wearing hair down to their shoulders or had giant afros.
I think she probably would have had a different physical design, but her character would've still been the same. I think it could have been an interesting idea.
She was too sweet. She would have been better off in TNG. Although I think she was probably there in the form of Troi.
I really liked Ilia, it was just such a shame that she never got much development in TMP other than the fact that she was Decker's love interest. Having Ensign Ilia at navigation would have been interesting, given the crew a bit more diversity and opened up a new possible storyline--there is actually a woman onboard who Kirk can't bang for legal reasons! That would then see Lieutenant JG Chekov as security chief...I wonder how long he'd survive in a redshirt?
Shaving her head was one of the worst things ever done ever. Incredibly, it worked well for the character Ilia Probe. For the human(oid) Ilia, not so. For TOS 4th season, probably one would have that idea as it was Rodenberry's and he was somewhat disconnecetd with Star Trek at that time. Who was the producer in the 3rd season again? I forget
With Ilia as a permanent crew member you´d be facing the problem of her (sexual) attractiveness: As soon as she appeared on the bridge in TMP all men started acting like dorky schoolboys. So either they´d have had to come up with some in-universe explanation that Ilia´s "influence" somehow wears off after a while, or you´d have ended up with a bridge crew permanently drooling on their consoles That being said, I liked her in TMP and she fit well into the overall "mood" of the movie. For a fourth season of TOS however, I think she would´ve been a tad too boring as a character. Mario
Her pheromones kick in in new situations, unless she takes regular pills/shots/whatever that regulate them - except during her cycle when they kick in full bore, allowing the occasional story where she's supposed to stay in her quarers, but an emergency forces her out and all the males are distracted. That's my story, and I'm sticking to it...
Eh, Kirk kept his hands off the female members of his crew as a matter of principle anyway (except under unusual circumstances, of course). Now that would have been a great running gag in a fourth season - Chekov getting in one redshirt-killing moment after another, and surviving by the skin of his teeth! Barely any trace of that made it into the final version of TMP - no way in HELL that would have made it past the network censors of 1970.