Re: Mr. Spock instead of Sir or Commander
We have met several pipless, enlisted nurses or medtechs in the TNG era where Ensigns stand out clearly due to their collar pips. Yet the prominent head nurse of Dr. Crusher, Nurse Ogawa, was an Ensign.
Not to mention she was promoted to Lieutenant JG near the end of TNG.
"In the name of the best within you, do not sacrifice this world to those who are its worst."