You bring up some interesting points. In my mind, though, Princess Pilar was heading to the church in a carriage from somewhere nearby, such as lodgings in which she and her parents had stayed, rather than having made the journey all the way from Bavaria in the carriage. Also, from all the research I've done, the Grand Duke Konstantin brought up his children to be as Russian as possible- making sure they spoke Russian at home, etc. I think that eating borscht and kasha could well be a part of that. Even Nicholas II was known for his simple eating preferences.
In addition, while the Grand Duke Konstantin's homoexuality (or bisexuality, depending on how you read his situation), may be well known now, he ordered that his diaries be sealed for several decades after his death. The research I've seen says that his family followed that order to the letter, so they would have been unaware of the diaries' discussion of KR's homosexuality. The evaluations of this that I've read suggest that KR's family would have been quite surprised by his homosexuality, given how he conducted himself in his family life. As a result, this novel doesn't really explore how his homosexuality could have impacted his relationship with his children. Also, given that Prince Konstantin had proposed to Princess Elizabeth of Romania, and was also said to have been interested in the Grand Duchess Olga Nikolaievna, I thought it unlikely that he would have been homosexual himself. One thing that I love about fiction, though, (and especially historical fiction) is that another writer could have written an alternate life of Prince Konstantin, and done it very differently. I agree with you about what KR might have been thinking to himself during the discussions about Prince Konstantin's potential choices for a bride, but since "Through the Fire" is from Prince Konstantin's point of view, we don't really see into KR's head at all. If I were writing a book about KR himself, though, I think his struggles with his sexuality would be front and center.
Thank you for taking the time to read my short story "Dark Night, Bright Sky." I think it's really kind of you to have sought out my other work. I disagree with your assessment of the short story and how it should have been written, but I'm not sure that this is the place for a discussion about it, since the story is completely separate from "Through the Fire" and has nothing to do with the Romanovs.