No lines of dialogue in TNG or DS9 ever says that Romulans don't use Dilithium in their warp drives, and Nemesis does say they mine Dilithium on Remus.
While not canon since it never appeared on screen, Rick Sternbach did make a labelled diagram for a Romulan Singularity drive that mentions it uses dilithium.
Exactly. Dilithium is not the power source or the space-warping mechanism, it's just the thing that channels the high-energy plasma from the former to the latter. Starfleet drives create that plasma using matter/antimatter annihilation, Romulan drives do it by compression in a microsingularity's accretion disk, similarly to the drives in Arthur C. Clarke's novel
Imperial Earth.
It was established as far back as "Mudd's Women" that ship's power was fed
through the "lithium crystals," not generated by them. Maybe that's the reason so many different stardrives use dilithium. They may use different means of creating their power and different mechanisms for warping space, but perhaps dilithium is simply the best known substance for channeling high-energy plasma in whatever kinds of drive require it. After all, it would always take a huge amount of energy to warp space, regardless of how you generate it or utilize it. There can't be a lot of different substances that can survive channeling energies on that level, or can do it as precisely or efficiently as dilithium.
For instance, I can't help wondering what behave of that dilithium recharger that Princess Po created on Discovery. Even 1000 years later, after the Burn, they aren't willing to share it? Why?
It was a dilithium recrystallizer, and it's a moot question, since Spock independently invented dilithium recrystallization a few decades later. TNG established that recrystallization was a known, routine technology by the 24th century. For that matter, the season 3 premiere established that Book had a dilithium recrystallizer on his ship.
I think the dilithium-scarcity issue in season 3 wasn't so much that they lacked the substance (though that was part of it) as that they didn't know what had caused it to detonate or whether it would happen again, which would've made people reluctant to risk using it more than they had to, or stockpiling too much of it in one place. Although admittedly that's not the impression season 3 tended to give.
I don't think SNW has made TOS better or worse... it's simply expanded it. It has done a better job with characters like Chapel, Uhura, and T'Pring.
But that was the question -- not whether it made TOS
as a whole better or worse, just if there were ways that it made elements of TOS seem better or more meaningful in context. Basically, things that you'd enjoy more about TOS if you rewatched it after seeing SNW, things you see in a new light now because of what SNW established.
Has it occurred to anyone that she can be vindictive and logical at the same time?
I repeat: This has never been about whether she
can be that way, but whether we
want her to be. If what she did was entirely optional, it makes her a far more monstrous person than I'm willing to accept.