The DA games have been much better in counteracting that effect than the ME games, but it's still noticeable enough that most romanceable characters don't feel quite like the PC's equal. So, yeah, I would rather like to see what a relationship with someone like Calpernia is like, but she should never become a companion. Whether rival or ally, she should be equal in stature to the player character. Undoubtedly that would make the majority of players hate her, but then there have always been romances that appealed only to a minority. I would also hate it if a romance compromised her character, for instance by making her change her goals to something more acceptable from the viewpoint of the feel-good morality Bioware so often employs in their stories (again, less in DA games than in ME, but still prevalent).
In the end, all I know is that I would like to see Calpernia again in a future game. As herself, i.e. not changed more by implied character development than Morrigan was between DAO and DAI.
I think the Dragon Age games have had a good balance actually. DA:O's highest ranking player character is a Cousland, who can act as Teyrn/Teyrna of Highever. The female can pair with Alistair, who is a half-prince, but still an heir to the throne. Even the male Cousland can marry Anora. In both cases there is joint rule. So that's equal. The lesser ranking characters have their equals as well. A mage has Morrigan or Leliana. A city elf has Zevran. Then in DA2 there were of course the lesser ranked romances, and a high ranking female Hawke had Sebastian. In DA:I it's not as equal, true, but my male human mage had Cassandra, who I believe is on equal terms with the Inquisitor. She may not run things, but she can be the leader of the Seekers, and her declaring the Inquisition made it all possible. My mage saw her as an equal and treated her as such.
Calpernia should be the leader of the Venatori who abandoned Corypheus and his cause, or continue it in their own way (if she never learned the truth). So I don't see how you make a character equal to a woman who leads a revolutionary cause.
More than likely, Calpernia won't be romancible. She will either be too involved with her cause, or she won't trust anyone enough to get close to them. And she might still not be over Marius.