Yes, I agree it had a lot to do with those things. Like I said in the other thread, Zenaida was disowned by Alix because she told her to get rid of Rasputin. There are letters on this site that prove Zenaida, Ella (her friend, Alix's sister, and Dmitri's aunt who raised him) and Anna Rodzianko (Zenaida's cousin, and wife of Duma president Michael Rodzianko) were discussing and plotting against Rasputin for awhile. They wrote in code for each person, Rasputin being 'the book', his supporters 'read from the book.'
Not only was his mother shamed by Alexandra, Ella (who was also very close to Felix) was also disowned and 'thrown out like a dog' because of Rasputin. In addition, Felix's father, Old Felix, had lost his job as a sort of 'Lord Mayor' of Moscow because of Rasputin.
Michael Rodzianko had been quoted as saying he'd kill Rasputin himself if he weren't so 'old and fat.' So there was a very deep rooted hatred and conspiracy against Rasputin involving Felix long before the murder. Many people Felix knew hated Rasputin and wanted him gone.
This was no way a spurned lover type of thing. From what you read of Felix, he was obsessed with youth and beauty, and would not have been sexually attracted to the dirty, scruffy, smelly, older Rasputin. I believe he was fascinated by him, but had no physical attraction to him.
Another part of the intrigue is that Felix was also friends with Munya Golovina, one of Rasputin's biggest supporters, and also was a lifelong acquaintance with Anna Vyrobova, maybe Rasputin's biggest supporter after Alexandra. It's all such an interesting story, I suggest reading a variety of books on the subject to get the best objective view of it all.