King Daniel wrote:
Of course, the real life reason is that an easily achievable undo button robs any story of consequence or tension, so they just pretended it didn't exist.
Indeed, the TOS crew had enough arcane knowledge to screw up most stories.
(1) They knew that traversing the galactic barrier produces Q-like powers in "espers" (Where No Man Has Gone Before). Granted, espers became super-powered dickwads, but if they were really up against it, they could do it by warping out to the galaxy's edge.
(2) They could simply synthesize a potion to give them the ability to conjure tremendous telekenetic abilities (Plato's Stepchildren - recall that these powers were used with great effect on the orbiting Enterprise).
(3) They could synthesize a potion to allow them to live and act at tremendously high speed (Wink of an Eye). Sure would come in handy during a crisis.
(4) They could time travel at will (Assignment: Earth).
(5) They stole a cloaking device, which they never used again (Enterprise Incident).
So there it is, they could go backwards in time, speed up time and run circles around enemies, create pyschic powers at will which would allow them to hold starships stationary in space, and they could make their ship invisible.
Sorry, but if I am captain of the Enterprise, I am reaching into that bag of tricks when I meet the next big bad.