I love 'Rebecca', though not the character, of course.
Hmm. I think Ms Danvers had an obsession for Rebecca, perhaps sexually, I don't know. But I personally don't think Rebecca would have even considered Ms Danvers--she appeared to me far too shallow.
And as for the separate beds, that was very common in those days. It's actually a rather modern custom for two people to share a bed every night (except for the poor people, who had no choice). A lot of rich men had mistresses.
I never got why people saw Maxim as a heartthrob. I found him a vile pig. But I'm glad, because 'Rebecca' is far more than a shallow romance.