Kevin, there is little difference between the "last resort" and your "redlines". I get your point, and absolutely agree that many people will choose a last resort that is simply too late. Your redlines and mine may be very close and very similar - I suspect they are, given our similar histories. I strongly believe that any individual needs to consider where his redlines are in the cool light of day and not in the heat of the moment.
A friend with whom I grew up used to be involved in many fights, primarily because he was a member of a gang. You could visually watch his body transition into "fight" mode when he decided a fight was coming on. I would tease him that he reminded me of when a shark rolls its eyes back as it bites its prey. He was very keen at discerning when a a situation was heading south.
I think good tactical programs delineate the indicators of an imminent tactical situation and the desperation to recover control in a situation. They discern ideological perspectives from pragmatic solutions and often tie your ideological constraints to your tactical solutions, for good or bad.
There's a difference between understanding the guy asking for a light is receiving permission to break your personal space barrier so he can move within attack range and defending yourself from a guy that just asked for a light and hit you in the face.