Seven's reactivation of the disabled Borg Cube was the high point of this episode for me. I would not have thought that an ex-Borg was capable of impersonating a queen and taking command of the cube.
Well, she is Borg and she was one of the unique ones. So, her impersonating and knowing all the kinks in the BorgCube and what to do with the Queen's Chamber tells me that there wasn't just one queen. There were many to replace her. And when she spoke, she spoke in the Voice of Borg as she took the collective in and felt all those hundreds of deaths.
In a way Romulans did everything they could to prevent full activation, and they had a backup plan just in case it happened. But they never had planned inflicting massive damage to the cube. Now it's repaired and helmed by Seven-of-Nine. We can speculate that she's able to engage the drives and assume flight to follow the Romulans.
Still, Seven's brief time as a pseudo-collective did seem to exact a toll. I suspect a longer stretch would prove fatal.
I assumed that she was taking toll because of the separation, not because of the collective. She wants to be part of it.
I wondered why she didn't block Narissa from opening the cube and mass-jettisoning the reawakened Borg into space.
She is a Borg, but she is also a human, and that human has been in control longer than she has been a Borg. At the moment she activated the Collective, Narissa turned the switch. In other words, the Hivemind became suddenly one or very few. We don't know how many of them survived, but it cannot be many. But what I mean is that the Borg has weakness in surveillance. They don't see everywhere. And they need drones to act as their eyes. Take those out and the Queen cannot see.
Elenor don't know anything. He has never really encountered Borg's in the full might. If he would, he would be careful around Seven-of-Nine. I like that he's young and innocent. He doesn't at all about the reality and what's going on in the Milkyway. Most of all he doesn't have those social experiences that Travellers have. I really wish that Elenor would meet Ferengis.