"She does use the tracker-jackers on the group below her tree, with full awareness of the possible lethality, so it isn't even like she was trying not to kill anyone, either."

Absolutely! She made the choice and the action to drop the nest of the wasps when she was in that tree. She knew what it would do and she did think about it and make that choice. It caused 2 deaths (in the book it was 2 though in the movie it was only 1) and it's not like she was shocked by that outcome. Dropping the nest of deadly wasps is not that different from throwing a bomb, I don't see how anyone could argue that Katniss did not make choices or that she chose not to kill.

Katniss could have just stayed up in that tree and who knows something else could have happened to remove the threat of the careers without making Katniss be responsible for the deaths.

The Rue thing... It kind of makes me wonder, let's say Rue is not killed and it's the end of the Hunger Games and the 3 people that are left are Rue, Katniss, and Peeta. What happens then? If Katniss values Rue's life over her own, does Peeta respect that choice or still seeks to keep Katniss alive at any cost? Does Katniss kill Peeta and then herself so that Rue can live?

Or does Rue somehow manage to kill them both to be the victor and her innocent angelic thing was all a clever ruse? Or it wasn't a ruse, she's still the same Rue but when it comes down to it she wants to live and values her life over the life of her friends.