Any sort of chase between a Borg ship and VOY would've been pointless. The end result would still have to be something destroying the Borg Cube.
They didn't do a "Borg try to take over VOY" story because they already did that with the Kazon, and plus they'd lose too many people in the attempt to assimilation for the show to continue on. Plus the Kazon only took Voyager because of internal sabotage.
The audience STILL wouldn't give a damn about random aliens being threatened by the Borg. in BOBW it was humanity and Earth itself threatened so folks cared, in VOY they don't have access to Earth, only Delta Aliens and no one would give a damn about any of them.
The Gamma and Delta Quadrants were mentioned in TNG, like in "The Price".
The Rebel Borg were just using what they commandeered from the rest of the Collective. They didn't make the conduit they stole it from the Collective.
Picard says in BOBW that for the Borg Cube to get from System J-25 to the Federation so soon, they must have superior power and propulsion.
What I mean when I say "Overpowered" is that I don't think making on Cube so powerful was a good idea. One Cube shouldn't be enough to take over the Federation.