1. How does a complex plot and/or realistic character development affect the erotic appeal? Increase it? Decrease it? Makes no difference?
The characters, at least the focal ones, have to be three-dimensional, complex personalities, with feelings, motives and inner conflicts that I can identify with. That doesn't necessarily mean a lot of psychologising or internal monologues, but what they do and say must reveal credible complexity.
2. Does historical accuracy/realism of setting matter?
I like vivid description and scene-setting, not over-done, but enough to draw me in. Blatant anachronisms or other factual blunders can be distracting, but in fantasies I don't expect over-precise accuracy/ realism.
3. Do you have a strong preference for a level of severity and consensual vs non-consensual or is the quality of the writing more important?
For me, th quality of the writing is very important - the choice of appropriate, original words and phrases, even the sound and rhythm, make a big difference. I'm not squeamish, but detailed anatomical descriptions, blow by blow descriptions of torture or sexual abuse, soon become tedious and lack the variety and psychological insight of good writing,