So Putin has just very publicly demonstrated that assassination is a justified use of conflict resolution to the world (and Ukraine).
<https://en.wikipedia.org/wiki/List_of_Soviet_and_Russian_ass...>
Several of those are in Arabic / Islamic states (Syria, Afghanistan, etc.), but numerous others have occurred in Russia itself, in former Soviet states, and in independent and Western states including the UK, Turkey, and Germany. A large number appear to be political rather than military targets, notably of journalists and opposition politicians.
To an armed insurrection? It's sort of the default.
He doesn’t. If he had, Prigozhin wouldn’t have gotten as far as he did. Putin needed to know that when he gave the kill order, it would be obeyed. The entire Russian state is in such embarrassing shambles that this isn’t an order he could confidently issue without serious concern that it would circle back on him. Hence the stab in the back; Moscow couldn’t survive a serious trial, a fact almost evidenced by the success of Wagner’s march.
Judges and legislators don’t keep dictators in power, armies do.