Real threats as determined by a jury.
What you are asking is like asking 'what is a real threat a person with a gun could perceive, where the person is not overtly pointing another gun (weapon) at them, such that a jury would decide, using the reasonable person test, that it was justified self defense'.
That is not something easy to answer as in each case you would list, it would be possible, based on very specific instances that the answer would be 'justified' in some cases and 'not justified' in others.