Cullen turned my qunari down.
I did a human run just to romance him because, like you said, it felt fitting for him to fall for another mage after his history with Amell; this time one who reciprocates his feelings.
I do have a problem romancing non-companions though because you see so little of them.
Cullen only romances Humans and Elves, but seeing him with a tall female Qunari would have been awesome! Lol
Yes, that's why I like that one quest where Cullen joins me.
I love how like in DA2, whoever you romance or whoever you are a good friend to, reacts if you get hurt in the battle. Having Cullen in the party and romancing him might have made that even more interesting!
My Iron Bull though, simply adores my Inquisitor and never lets her fall in battle. Any enemy hits her, he charges at them! I found Zevran did that too with my Warden, even though I didn't romance him.