To be honest, they could have done more with Jake in the final two seasons if they wanted to, they just didn't. He was a reporter during wartime, he could have travelled to different worlds to witness the war, broadening the scope of the conflict in the process. But they either didn't have the money or the inclination to do it. Also, the original concept for In the Pale Moonlight
was a good one, and if they didn't want Jake getting into conflict with his father due to their bond then they could have had Jake investigate some dodgy dealing that Martok and the Klingons were up to. But they just dropped that whole concept instead, which is unfortunate as exploring the role of the media and whether they can be harmful to military strategy during wartime would have been something interesting to explore.
Playing God (*½)
I've been thinking, the Trill aren't all that interesting as a species, are they? I'm not talking about individual Trill characters, but the species as a whole. They've got this gimmick with the symbiont and nothing else, all Trill stories revolve around that one thing in some way. We know almost nothing about their culture, their politics, or their traditions beyond those that relate to the symbiosis (even though 90% of Trills aren't joined). Compare that the the Bajorans, the Cardassians, the Klingons and others, those are species with defining traits but we get to see multiple angles of them as a species. Even the Fenergi have two avenues to explore, their greed and their misogyny. But the Trill have just the one, and it's interesting for a bit, but there comes a time when you feel that they're making too many trips to the same well.
The main plot of this episode revolved around Arjin, a rather uninteresting Trill that wants to be joined, and how Jadzia judges him unworthy of the opportunity because of just how uninteresting he is. I suppose the core of this plot is about how Jadzia is still upset about being thrown out of the initiation program by Curzon due to his abrasive and judgemental attitude to her, but now she finds herself acting in a similar way to him and she tries to reconcile those two elements of her personality to find a solution that works for the new Jadzia Dax. Or something like that. It's well meaning, but it's just not that interesting and neither is Arjin.
Then there's the b-plot. The crew has made the greatest scientific discovery of all time, an actual universe within our own, one that even contains life. So it's extremely underwhelming that this amazing discovery is reduced to a ticking timebomb that will blow up the universe in a couple of hours if they can't find a solution. In fairness, it tries to be more by having Sisko tackle the complex moral issue of whether or not to destroy the new universe to preserve his own, but it feels awkwardly added on to a plot that's already outrageous in how poorly it handles this gargantuan concept. To be honest, the concept just doesn't suit the show. DS9 doesn't do high-concept sci-fi well, and this is the highest of all concepts imaginable. DS9 is more grounded in characters and societies and how they interact with one another, so hearing Sisko do a log entry debating the fate of two entire universes just doesn't sound right. On TNG or Voyager this plot may have stood a chance, but on DS9 it sticks out like Steve Bushemi at a Scandinavian male model convention.