SNM:
Ezri + Bashir: fortunately for Ezri, Bashir is only a partial Augment, so his strength isn't going to be a problem. I definitely see Ezri as the sub here; by the time Ezri was introduced, Bashir was a really strong, self-assured alpha male, and she's meek and naive as well as really, really annoying. I imagine that she's usually (if not always) the patient when the two play doctor.
Well, I would venture that Ezri Dax was gradually 'growing into' her role on the Deep Space Nine station during the final season (her character's only one), just as Doctor Bashir gradually developed self-confidence in his competence over the show's first several seasons--he was once struggling with self-esteem issues also, but he grew out of it as time passed and he gained experience.
So I would expect Ezri to do that also, and one must remember that she'd undergone what must've been a truly traumatic experience, suddenly and unexpectedly (and without training or preparation) being merged with the Dax symbiant. In the long run, she'd have all the accumulated experience of the previous Dax hosts to draw upon (once she'd adjusted to the dramatic change), so I would expect her to eventually become (as Jadzia was) a psychologically strong individual.
(One sees this occurring by the end of the series, for example she's the one who convinced Worf to challenge Chancellor Gorkon over the increasing corruption and dishonor within the Klingon Empire.)
IIRC Ezri and Julian (Bashir) were the only regular cast members left serving on the station at the conclusion of the DS9 series, it's interesting to speculate RE how their relationship (whether it would've involved spanking or not) would have evolved afterward. (If there were CP involved, I'd expect that it would end up as roughly 50-50 'switchish' between the two of them.)
I was glad to see Julian finally find a romantic interest, after being continually 'shot down' by Jadzia with her "Let's just be friends" mantra during the first few seasons of the DS9 series.
If a joined Trill woman doesn't want to be your girlfriend, just wait until her symbiant is in its next host--if it turns out to be a another female anyway--and try again... --C.K.