It's pretty standard tornado hunter stuff, really. Whether it was written with that intent or not is quite irrelevant, as the interpretation makes obvious and intuitive sense.
Kirk sailed deliberately into an ion storm when he clearly could have avoided it (the ship is approaching the storm and not vice versa, says the helmsman), and initially made no attempt to leave ("hold your course"). He was keeping close watch on how the threat to the ship gradually increased, and was going to cut and run, but only after achieving something.
What he did wait for in actual fact was the jettisoning of the pod. He even had his command panel configured for that very action. It thus very much seems this was his mission objective: to jettison the pod. It just had to be prepared first, by somebody suitably competent, but he had no standing specialist for the task, apparently because it was a very rare one. And the preparing had to happen while the ship was already flying into the storm because of the same thing: the rare storm would dissipate if Kirk waited to prepare the pod first.
Ben Finney counted on an ion storm for his dastardly plot. But he had been plotting for
years! Storms thus do appear to be relatively rare things. (Or was Finney skipping eighteen storms and waiting for the nineteenth so that him having the pod shift would not look too suspicious?)
That the pod would pose a danger to the ship is never indicated. The storm poses a threat. But the ship has to stay inside the storm until deploying the properly primed pod.
What part is left unclear or mysterious?
Or Finney really hadn't plan the whole thing out, but a soon as he was out of the pod and it was jettisoned behind him he recognized an opportunity, and went into hiding, and altered the records.
This is a less preferable interpretation, as what Finney did does require some preparation. He needed his place of hiding, for one thing, and he couldn't prepare it after the fact, while a thorough search was going on "in and around the ship".
As for the ion storm in "The Galileo Seven", we have two things to consider:
1) Kirk already had two pressing priorities there, the delivery of the medicine and the rescue of his missing team. Combined, enough reason to skip scientific research? Clearly, the medicine matter alone didn't stop Kirk from studying the Murasaki phenomenon and region, and the local ion storms might in fact have been part of the attraction.
2) Kirk nevertheless didn't send his ship in there, but a shuttle. Perhaps there are limits to what dangers a starship may brave in order to get ion storm data, and Murasaki just upped the ante too high?
In "Mirror, Mirror", there was no mention of a storm - except in the Mirror universe! The Imperial approach to storms might have been to avoid them unless flying through one made tactical sense in combat (or made the skipper look brave).
Timo Saloniemi