Ironically, the Orin kidnapping thing is taken straight out of BG2 but implemented pretty poorly, when you first see your Romance disappear into thin air after Bodhi's dialogue, you start sweating bullets... (unless you are romancing the "A MAZ ING" EE companions that just "... you thought i'd need to be saved? I DON'T NEED NO MAN/WOMAN")
I've seen Viconia disappear so many times i've lost the count but it still gives me the same exact feeling of urgency every time, it doesn't matter that i know she's just a few chambers away under the graveyard.
The way you also have to carry your Romance's body afterwards, running like a madman/woman to Amaunator's temple and the dialogue at the altar also really add to that... solidifying the fact your Romance is really important.
Yes! It's a very interesting and really emotional quest, it's nice to remember. I still played the first playthrough without the romance and after the dialog with Bodhi in the walkthrough with Viconia (especially since I was totally not expecting it, I thought I knew the game and it turned out Bodhi just didn't have a reason before) I myself just had a definitely emotional line burst out. The sense of urgency - it's definitely very easy to understand him (the character) and imagine what he's feeling right now. There's no other way to play it other than running like a madman.
Orin, of course, can kidnap not only Halsin, but also Lae'zel and Gale, and those players who have a romance with either of them can also experience something similar. Orin kidnapped Lae'zel first, and I myself sinned with a spoiler, as Lae'zel is an important fighter, I absolutely did not want to sacrifice her, and I was too eager to destroy Cazador, I was terribly reluctant to dismiss that and go after Lae'zel, anyway, Orin decided to get into kidnapping at the wrong time. But when I found out that I could offer her Halsin, I couldn't resist. Maybe it's also the fact that in BG3 there are fewer companions and they are all tied to the camp, so it's hard to get rid of someone you don't like, except to kill him, which, in general, breaks the roleplay, and makes Tav some kind of inadequate. There's no option to kick Halsin out, which is odd, he doesn't have a larva, he's in no danger of turning into an illithid, so kicking him out would presumably be safe, without the whole "sending him to his death" thing. In BG2 we've been tailoring the group to ourselves over time one way or another, I think kidnapping any companion from those I've chosen myself would give me a sense of urgency and even without the romance. Admittedly, there was no such urge to get rid of someone as there was to get rid of Halsin, either.