Yeah im sure she knows exactly what she was doing when she allowed the film to be directed in a manner that plays Armand as a full grown man as opposed to the youth he was when Lestat met him.
She had nothing to do with the film. She saw it when it came out like everybody else. And thought Cruise did a great job.
Im even sure she properly thought out the difference between showing the interviewer being turned by Lestat at the end when in fact that never occured and he was only ever turned by Armand years later.
No novel-based movie can follow everything perfectly. The novel's ending would not work for the film anymore than the ending in Jurassic Park (book) would work in the movie. So both writers/directors decided on something more interesting.
As far as Rice goes she hasn't done shit in terms of doing right by her literature.
It still is her literature and she knows how her characters are more than you or I. Simple as that.
Even the longing for humanity was perfect where as in Cruise's case he was far too pre-occupied focusing on being the anti-christ than being the character (albeit Louis did supposedly take the piss with his account of details)
He's only wrong according to Lestat. Lestat could very well just be making himself look better.
And there was no longing for humanity by Lestat in Interview (book). He was 95% of the time a sadistic asshole.. Even in kind acts like with his father he was unable to be truly human and it fell upon Louis.
The other 5% of humanity is only seen twice in the book:
a. in Paris.
B. when Louis finds him later in his story.
So Cruise played a demon because Lestat was a demon in the book. It's not his fault that Lestat was made more an anti-hero and not a villain in later installments.