По поводу идеи Александра III женить наследника на Елене - интересно отыскать источник этого слуха(?). Самое раннее, что я нашел, это изданная под псевдонимом в 1918 году книга некоей княгини Екатерина Радзивилл Confessions of the Czarina. История излагается в ней так:
At this time, when his father’s life was trembling in the balance, the heir to the Russian Throne, the Grand-Duke Cesarewitsch, was twenty-six years old. If the traditions of the House of Romanoff had been adhered to in regard to him, he ought to have been married already, as it had been settled by custom that the eldest son of the Czar ought as early as possible to bring home a bride, so as to insure the succession to the crown. But the Empress Marie had never looked with favor at the possibility of seeing her family circle widened by the advent of a daughter-in-law, and whenever the question of the establishment of her eldest son was raised she always found objections to offer against any princess whose name was mentioned to her as that of a possible wife. The French party at the Imperial Court, which at that moment was in possession of great influence, tried hard to bring about the betrothal of the future Czar with the Princess Hélène of Orléans, and at one time it seemed as if it would be really possible to arrange such a marriage, in spite of the difference of religion.
Мне кажется, что книга основана скорее на слухах, чем личном опыте, но интересно, что в 1918 об этом уже были слухи (если, конечно, Радзивилл не выдумала все это от первого до последнего слова).