Instead of blowing up the shuttle capable of instant transgalactic flight because she couldn't trust Starfleet to use future tech responsibly, Kathy could have trusted at the least her own crew to use the technology responsibly and then try to blow up Voyager, or just the time drive, after they had used the time drive to get back to the Alpha Quadrant before Starfleet could get hold of it.
The Time Drive was unstable and breaking down, but if B'Elanna and Harry looked over the technology for a month, they could have built a new one, even a better less wiggy time drive, that wasn't wearing down on the verse of catastrophic faliure, and jumped home without any problems or having to contend with the Borg.
It's possible that Janeway massaged the truth until her yonger self thought that it was her own idea for the old lady to whack the Queen? But really? Whacking the queen using a virus similar to something that was already floating in Ichebs blood stream and everyone Icheb had had sex with.
Just a by the by.
Becuase of Endgame, 63 billion Federation, Klingon and Romulan citizen's died in the novels as payback for what Admiral Janeway did to the Collective.
If there was a reason to backstep and stop Endgame you would think the number of fatalities that might be averted would be considerably less than 63 billion souls? Of course 63 billion people died, but not Seven of Nine.
Was that when Kathryn died?