The impression I got from the large amount of debris the Enterprise-D and Titan flew through in the epilogue was that Spacedock had managed to destroy or damage a large number of starships while they were under Borg control.
Perhaps... but Spacedock lost that battle. (When it keeled over, I was terribly afraid they'd do the stupid thing of having it "fall out of orbit" in a complete misunderstanding of how orbit works.)
As for the Supercube -- I got the impression that its weapons were less powerful than you might normally expect as a result of it having such a small compliment of functional drones, operating at only 36% capacity, and dedicating most of its resources to transmitting the control signal.
How would the number of drones have an impact on the power of the weapons?
The Matrix notwithstanding, there's no way humanoid bodies' metabolic energy could be a useful power source for a technological system. If anything, the lack of drones to maintain and control probably freed up more energy for other stuff like weapons.
I was tempted to ask why the hell a Borg cube would have so many weapon emplacements
inside itself, but I saw a photo on Twitter pointing out that the Supercube was assembled from many smaller cubes, so a lot of their surface weapon emplacements would be in its interior. That also helps account for why there's so much open space inside it.
Completely agreed. I'm sure the Enterprise-D/Syracuse was pretty badly damaged towards the end there. In fact, since really the only parts of the ship that can know canonically must have had life support are the bridge, the transporter room, and the corridor they used to get to the turbolift, I think it's entirely possible that large portions of the ship might have lost life support or been exposed to space due to hull damage.
On the contrary -- being vented to space would reduce the damage. In
Gene Roddenberry's Andromeda, which was initially a hard science fiction show with a JPL engineer as its science consultant, it was standard combat procedure to concentrate the crew in a few small areas and vent the rest of the ship to vacuum. That way, when relativistic projectile weapons penetrated the hull (since there are no deflector shields in a hard-SF universe), there was no internal atmosphere to propagate and amplify the heat and shock of their impact, so much less damage was done.
So really, if only the bridge and a few other decks were pressurized, the E-D would've been less susceptible to damage than if it had been pressurized throughout.
I thought the D was a total loss at the end of Generations.
It was. The saucer was largely intact, but its frame was surely damaged too much by the crash to make it practical to put it back into service. But Geordi was the director of the Fleet Museum and was able to devote years of effort to restoring the saucer and mating it with the battle hull of the
USS Syracuse.