Re. rape fantasies - yes, a not insignificant number of women have them (I write fanfiction, so I know this all too well - they are remarkably prevalent in what is a female-dominated subculture, where predominantly women write for a predominantly female audience).
However, it is important to remember that such fantasies may be coming from exactly the same place - namely, a maladaptive coping strategy to the ubiquitous threat of male violence.
There are a number of "explanations" for their popularity, none of which hinges on the truly stupid idea that women actually want to be raped.
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what you might call the classic lib-fem explanation: they're not about rape at all, they're a metaphor for being overwhelmed by passion in a world which tells you that female sexuality is so wrong that the only way you can allow yourself to let go and enjoy sex is if you were "made to do it." (I have talked to women from US fundy Christian backgrounds who say this is in fact an accurate description of the way their sexuality got distorted by their upbringing.)
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The rad-fem analysis: male sexual violence is so widespread that a form of society-wide Stockholm syndrome sets in. Some women eroticise their sexual oppression because they use it as a coping strategy to avoid facing up to the fact that if they don't consent to sex, it may be forced upon them anyway.
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As a form of cathartic working through of events after someone has been raped - fiction becomes a way of re-working the narrative in such a way that the reader/writer is in control.
All of these, it seems to me, are coming from exactly the same place as the young teen who opts to try to avoid being sexualised by men altogether by "identifying" as a man - they are all maladaptive coping strategies, forms of cognitive dissonance, to cope with life in a shitty patriarchal world.
What they are not is like the motivation of a male consumer of rape porn. A male consumer of rape porn's motivation is much simpler: he is identifying with the rapist and getting off on the idea of raping women. This motivation is entirely sinister, and why, while I have had female friends who were into rape porn, I'd run a mile from any man who admitted to enjoying rape porn.
And for the record, I do not believe the claims that "more women than men" watch rape porn on porn hub. I think that's an MRA crock of shit, like the "women and men commit DV in equal numbers" crock of shit (which basically translates as "we're going to count all repeated instances where the male perpetrator beats the shit out of the female victim as one incident, and give it equal weight to the one occasion on which the female victim shoves the man out of the way in her efforts to escape.)