Ooh, what a fun question! I really do like Merrill -- if you think about it she really is the most fresh-from-the-clan Dalish character/companion we get in DA, canonically (if you don't get a Dalish Warden or a Lavellan, it's at least nice to have Merrill there for the representation). Bellara and Davrin are Dalish, yes, but they seem a bit more removed from their Dalish roots, especially Davrin. (And part of that may be just the way VG treats Dalish in general, which is neither here nor there...)

I do feel a little bit like Merrill was there partially for shock value -- a Dalish blood mage whaaaaa??? But the more I got to know her, the more I liked the character they made for her. She's naive but principled, she's willing to do what she thinks needs to be done to protect her culture and her people, even if she doesn't always think things through the whole way. She's willing to learn more about the rest of the crew and companions, but she doesn't let them change her core, either. And even though some companions give her shit, by the end of the game she's confident (and jaded) enough to give them back a little bit of shit, too.

(And honestly, her naivete and general fish-out-of-water nature with culture shocks makes for some of the sweetest and funniest moments in the game. If Varric loves her, then so do I.)

I've never kept Carver alive, so I've never seen her romance with him (that's a thing, right? I think I heard that's a thing.) but I do conceptually find it a bit hard to wrap my head around. Maybe also because I don't know Carver very well at all. Regardless, she deserves to be happy, even if it is with a Hawke Jr. with, um, issues?

I was thinking of an Elven Rook dancing with Bellara and Davrin one night and its a Dalish dance. Bellara found and fixed an artifact that had a recording of some of their people's traditional music. One of the songs is something that was familiar to all 3, a dance that had been taught that perhaps was once traditional but after being lost and found again, looks a bit different but they dance feeling connected to their ancestors

Then I was thinking of the Veil Jumpers having a celebration one night and the Veilguard are all invited and the members who know little of Elven culture get to watch as the three elves lose themselves to a rhythm