I dunno if this'll make you feel better, but despite what Gaider said, it doesn't necessarily mean that Merrill can't be demisexual or only sexually attracted once emotional attraction takes hold.
Realise that a good number of people don't all have the same set of definitions at hand to describe a thing. Hell, a good number of people don't get there's something apart from being completely gay or completely het. Even here, people have different definitions for the same exact words. So, despite referring to her as bisexual, removing ambiguity in the sense that her sexuality does not change based on someone's choices in CC, it can still mean that she's warms up to people romantically the same way you've perceived before.
Yeah, I think I agree with you on this Krytie. Now that I'm becoming more familiar with the terms "pansexual" and "demisexual", I think that I can start to form my own "working definitions" of how I see these terms. For me, pansexuality is a type of bisexuality. It's a more "liberal" or "open" form of the idea that a person is attracted to multiple genders, without being limited to a binary. To bring it back to DA, I would say that Zevran, Isabela, Anders, and Iron Bull might all be pansexual (specifically Anders and IB).
Demisexuality, to me, is more of a modifier. As in, it's not necessarily a sexual orientation on its own. It's the way in which sexual or physical attraction occurs for some people. A person could be heterosexual and demisexual (or any other sexual orientation and demisexual). So to bring it back to DA, I could very easily see Merrrill as a bisexual demisexual. She needs an emotional connection in order for attraction to happen, but her attraction isn't limited to only one gender.
I see a parallel between 'demisexualilty' and 'transexuality' in the fact that they are not necessarily sexual orientations on their own. You can be a heterosexual, demisexual, transexual wo/man. However, they seem to get lumped into the sexual orientation category because they are "deviants" from the "norm" (hopefully, you see how I'm using those words).
This whole conversation has been fascinating to me. I love learning about stuff like this and it's interesting to see how we can use the characters from DA as a way to highlight concepts. Very cool stuff.