Use of "man-sized" props and sets serves another function where televised scifi makes compromises between reality and drama - or, amusingly, caters for both with the same solution. Sending the saucer to study a planet is 1950s thinking; by the 1960s, it would already have become clear that the one thing a survey mission does not need is people.
In the modern world, instruments do the studying, and people only get in the way if they don't sit in their comfy chairs and toy with the data on their VR displays. There's basically nothing realistic for hordes of extras to do, and it's difficult to invent "scientific" or "naval"/"astronautical" tasks for even a group of seven characters with lines.
A shuttle that accommodates half a dozen characters is a nice "compromise" in that it's a step that pleases both those minding the realism of the situation and those paying for the actors. We get machinery that goes ping, and we get people, and we get the sense of people going places.
And we get the impression that these folks should really be back in their ship for safety, that their mission automatically puts them in jeopardy, and that things like "lifeboats" or "abandon ship scenarios" would mean even greater jeopardy and would be avoided by the characters till the very last.
TOS really didn't capitalize on being in outer space enough; it took until "The Tholian Web" before we saw our heroes wearing spacesuits.
And that's realism of sorts, too. People up at the international space station would much rather never do spacewalks; once we go to Mars, suits will probably be donned mainly for the obligatory photo opportunities and extreme emergencies, and the way to actually get stuff done is to sit down at the control console and tell work to happen.
But that's a future that is in the
past of our heroes. They no longer should have to grumble about wearing a spacesuit, as taking a spacewalk ought to be as simple as taking the dog to her evening rounds. And in TAS, it is. Perhaps that's how spacewalks happen in most of the Federation, and Kirk's mission to the far frontier is an exception in featuring "excessive" protective measures - the difference between what to wear for -30C winter days in downtown Ottawa and in Antarctica.
When it comes to saucer-power, I always go back to "The Alternative Factor" when Lazarus steals dilithium from an engineering room that appears to be powering the ship even while in orbit; I surmised this was an impulse engine room and the dilithium was being used for the impulse drive.
It should be remembered that the dilithium in that adventure was essentially down for the count - it was being hospitalized because of what the interuniverse hiccups had done to it. IMHO, what we saw was a dilithium hospital, meaning that when the Lazari stole the (almost but not quite healed) crystals, they didn't deprive the ship of any of her currently available power (since everything still worked like it previously had - it took some effort to even notice that the dilithium was gone), merely of power that should have been available later on.
Doesn't mean I would disbelieve in things like saucer warp drive...
Timo Saloniemi