The NIFP sounds like a rebranding attempt to fix the NAP's obvious flaws. Haven't looked deep into it, but if it's just "don't use force unless necessary" then congrats, you've reinvented common sense.

The necessity defense angle is spot on though. Even hardcore legal systems recognize that sometimes breaking rules is justified when lives are at stake. It's wild that some libertarians are more rigid than actual courts.

The real issue isn't finding the perfect principle - it's that some people are so desperate to have an unbreakable rule they can hide behind that they'll sacrifice basic human decency. Philosophy should serve humanity, not the other way around.