To me, on my historical and point of view, of Prince Felix.
He was raised an aristocrat, known to be vain, snobby and imperious and also charming to though he likes. And use to get everything he wants, as a typical spoiled rich boy as his family was FABULAOUSLY Wealthy, richer then the ruling house.
In the 1900s to the end of the Russian Empire, for Russian aristocrats boys like him, being flamboyant and cross dressing were all the rage! And as being rich, thought to be immortal, like any rich or famous person now.
As been gay, I think he was more “Bi-sexual” since most gay men would then and even now would not consider marring and less mating with a woman; as a outgoing as he was I really doubt he’ll hid such as his gender and sexuality.
As for his wife Princess Irina, they were good friends and greatly understand each other which made their marriage last and happy enough. They both had love affairs (him with both men and women) after their daughter was born. He did say once, that Irina married him for his money, and he married her out of pride, think of it, he married the Emperor’s ONLY niece (by blood). Their marriage may not be passionate love but it was successful.
As for murdering Rasputin, I did remember reading once- in his memoirs, that he thought (and many even agree with him) that Rasputin and the Empress was destroying Russia’s government and he in his mind it was his duty to get rid of Rasputin for good.