“How different is it when soldiers are at war? They must kill or be killed.”
I think there is an important distinction between “kill or die” and “kill or be killed.” The wolf’s life may be at stake, but the rabbit clearly isn’t attacking the wolf. If I need a heart transplant, I would still not be justified in killing someone to obtain the organ.
I know this is a few days late, but I couldn’t help but notice that no one mentioned how your “Zenlike but not Zen” philosophy is basically just a weak version of Stoicism (weak in that you seem to desire some passion, whereas a stoic would advocate distancing yourself from all highs and lows). There is no need to create techniques to do this from scratch, the path has already been laid out. I would encourage anyone interested in the topic to research Stoic teachings, particularly Epictetus, if you haven’t done so already.
[I recommend Epictetus because there is an unfortunate tendency in ancient Stoic philosophers toward more mystical, almost religious, thinking. Epictetus refrains from that, for the most part, and concentrates on practical aspects.]