FF was in his own country.
I don't know, I can't remember any such event...
What are the precedents though? Of heads of state dying in foreign lands due to an assassination? (Obviously not Ferdinand since that's much later)
Well, Alexander king of Yugoslavia was assasinated while on a state visit to France in 1934. But France and Yugoslavia were allies, the guilty party were clearly Bulgarian-Macedonian terrorists (possibly backed by Mussolini) and the power dynamics were entirely different.
I vaguely recollect a few other assassinations carried out on foreign soil by anarchists and so forth but they aren't very relevent either.
I think the critical thing to remeber is that the racist issue and power-balance issue. The Russians are NOT treating this the same way as they would an assasination on German soil by a Pan-Germanist, or even on Romanian soil by a Bessarbian unionist. Issues of Balance in power, international law, due process, the concert of europe, and the whole alliance system would constrain any response.
But in this case, these are "Asiatics" and the assumption is that they must be taught their place.
Negotiations in Vladivostok are perfectly plausible, but IMO asking that Emperor arrrives there personally ON RUSSIAN SHIP are made if you want that Japan refueses and if you want war, not an agreement. Japanese did win in 1905. but they didn't ask that Nicholas II comes to Portsmouth, Witte was more than enough.
Different power dynamics. Russia may have been defeated on the field of battle but it's land reserves remained vast and she was prepared to continue the war. During the negotiations the Russian army continued to be reinforced and the TSR upgraded. By the time the treaty was signed reinforcement were arriving at a 250% times as fast as at the beginning of the war. If Russia had the political will to continue the war they probably would have won in spite of the incredible deficiencies in their armed forces (and entire system).
This is a different situation. Japan's cities are totally exposed to Russian bombardment. They have no allies and are not viewed as members of the family of nations by the other powers.
But you are right. This is a high handed, incredibly arrogant demand. It's on the same level of the French summoning the royalty of Madagascar or Vietnam to Paris and then placing them in exile in Algier, or of the British doing the same to the Zulu or Ashanti kings.
The reason I was inspired to do this scene is that the Japanese ministers had a very real fear, OTL, that Meiji would be kidnapped if he visited Nicholas on his ship to apologize.
TTL He isn't, not quite, but forcing his presence in Vladivastosk is a powerful negotiation tactic. The Japanese don't *Know* that the RUssians will release him if they don't get what they want. And given his centrality to their newly established political system that's enough to throw them into a tizzy and possibly cave to demands they would otherwise reject.
Still, if the consensus is that this ultimatum is over the top, then I can retconn it into an ultimatum to get to Vladivastosk within X amount of time. All else, you can assume that this isn't Tsar Alexander making the demand- It's grief stricken, hormone muddled, twenty year old George adding his own embellishments and risking war.