There were only a handful of Season 3 episodes which exceeded mediocre: The Enterprise Incident, Is There In Truth No Beauty, The Tholian Web, Day of the Dove, and All Our Yesterdays. Most of the season was unbridled shit.
That said, I'm glad it was made, because without a third season it's pretty unlikely TOS would have been syndicated in the 1970s, and we never would have gotten the rest of Trek.
I don't agree. In fact, I much prefer the tone and originality of S3 in many cases to the endless "Parallel Earth"'stories or "time travel to Earth's past" stuff that plagued S1 and S2.
Episodes you listed are classics. There are others that explored some great, unique sci-if concepts:
World is Hollow...
The Empath
Wink of an Eye
That Which Survives
Requiem for Methuselah
Cloudminders
Lights of Zetar
Looked at the characters in unique ways:
Paradise Syndrome
Straight-up Fun Adventures:
Savage Curtain
Specter of the Gun
Elaan of Troyus
...all of those are above-average outings when compared to a typical franchise offering.
And then there was crap:
Spock's Brain (which I actually also like)
And the Children...
Way to Eden (which I also like in a weird way)
Turnabout Intruder
...which was below average from the typical franchise offering, but still mostly not amongst the worst.
EDIT:
"Unbridled Shit" is Alternative Factor, Mudds Women, Code of Honor, Angel One, Datalore Aquiel, Imaginary Friend, Descent (both parts), Move Along Home, Threshold, 1/4 of Star Trek: Voyager and the episode Tripp gets pregnant. Most all of S3 is
far above this kind of crap, with the exceptions of Plato and Turnabout, which are shit.