So I've been doing a rough outline of my fic for page 3000 and I want some opinions.
I'm not basing my fic on what I think Cullen will be like, but on what could be a possible scenario due to his capture and torture in Kinloch.
Is it unreasonable to think he may have an aversion to intimate touch after the lengths the desire demon may have gone to to try and tempt him into succumbing? I don't imagine him having the appropriate means to fully work through something like that over the years and maybe just pushed it aside instead of dealing with it.
I hardly think this would be the case in-game but hey, it's just a little story 
I am dealing with the same question for my page 3000 fanfic.
Based on what I have learned from my writing courses character development works like this:
The character wants something badly but he has trouble to get it. His inner demons prevent him from reaching his goal. Therefore, he has to fight his inner demons/ his deepest fears In order to get what he wants. As a result the character changes - hence character development.
With that in mind, I think it is very likely that Cullen's torture in the Ferelden circle has some impact on him. How it affects him depends on the story you want to tell. If your story is about Cullen's desire to be intimate with someone, it makes a lot of sense that he actually has an aversion to intimate touch. He wants the intimacy, but he can't manage to break the metaphorical wall around him. He has to struggle to reach his goal and he has to overcome his aversion at one point. To see this struggle is the interesting part of the story.
Not sure if this is the answer you were looking for. Anyway, I hope I could help a bit
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