Ummmmm I'm not sure if all your facts are correct but that's mostly correct. His death was really nasty..... Let's just say that....
Master Of Ice
This is a rather late response, but s/he is mostly correct. He was not "put to death," as that implies he was formally executed, when he was actually assassinated. This was because Prince Yusupov and his followers felt that he had too much power in the Russian political affairs. He was, as reports say, a "mystic healer," and a religious man, but not a priest. He was referred to as a monk, although I do not believe he ever officially became one.
But let me tell you something, we may never know what really happened in his royal affairs and what the circumstances were surrounding his death, as after the Bolshevik Revolution took place, many documents were lost or destroyed. This allowed for many legends to rise, as if gossip wasn't spreading around Russia at that point anyways.
Although we all know what Polaris is based off of by now, I would like to make a comment or two towards some of the architecture in the world. I'll speak in regards to Walruskberg.
First and foremost, if you look around Walruskberg, you will notice a red brick wall that runs around it. This is most likely symbolic of the Red Square in Moscow.
The building with the mulitple coloured domes is a direct reference to St. Basil's Cathedral.
The building in the distance with only the gold dome may be in reference to Ivan the Great Bell Tower, but instead of having a white base (as the landmark has), it is brick to fit in better (this is just my theory).
And now the arch in the middle. This, to me, resembles the Arc de Triomphe in Paris, France, much more than it does the Triumphal Arch of Moscow (Moskovskie Triumfal'nye vorota). The difference is that the arch in Walruskberg is flat on the top, resembling the Arc de Triomphe. The Triumphal Arch of Moscow has a statue on the top (seiuga; six-horse chariot), as well as black touches on the columns and on some of the trim.
So there are a few architectural details that also enforce the idea that it is indeed a mash up of France and Russia. It is not limited to these, but I found them prime examples.