Implication that ROK politicians are proud Spartans and want to live less than Kim is questionable, since literally all of them end up in prison for corruption after their terms. They are people, and most people in power enjoy their lives.
Obviously not, but importance of individual leaders/state actors are vastly different between a democracy and a dictatorship regime. They are hence treated wildy differently in IR studies in predicting state actions and consequences.
Moreover, I don't know why this dumb discourse about a possibility of North Korean 20t warhead ballistic missile came out in the first place. This one person in the thread above our posts doesn't really seem to understand what a CONOPS is and is only interested in dick measuring contests, unfortunately.
The keyword here is deterrence. That's what I've mentioned above in one of my comments.
NK already has established and are expanding their strategic deterrence with nuclear deterrence. In grand scheme of things, a 20t warhead conventional ballistic missile barely adds anything, if anything, in terms of NK's deterrence against SK and the US
RoK doesnt have any strategic deterrence apart from US nuclear umrella, at least they haven't possesses any before the advent of Hyunmoo-5. It is still questionable if conventional deterrence through decapitation is an effective strategy against dictatorship (traditional IR studies deem decapitation an inadequate strategy due to risk management issues and escalation threat), but now there at least is the capability.
This is also the reason I've mentioned conventional deterrence and recent Israeli decapitation strike of Hezbollah as a possible role model.
On a sidenote, it seems like you are also making some gross exaggeration on your front with regards to Korean politics.