1) Someone finding a suspicious package and falsely thinking it's a bomb, and
2) Someone calling the police and saying, "I'm going to bomb Facebook" (when they actually aren't)
All of your arguments thus far have pertained to 2. You have repeatedly cited the definition of "threat" underneath that context, and scenario 2 perfectly satisfies that definition. Furthermore, so does "terrorism", because a bomb threat, real or not, causes terror and has high potential for real physical harm.
Under your definition, someone threatening to shoot you in the street wouldn't be a threat unless they actually shot you. In reality, intent is almost always impossible to discern and doesn't excuse reckless behavior. Should you not be charged if you didn't happen to kill anyone while driving home drunk?
You may disagree with Facebook's influence on this world, but advocating for methods that only cause chaos, potential harm, and disinformation is not acting in the world's best interest.
The presence or absence of malicious intent cannot turn a nonviolent act into a violent one, or vice versa.
I did not call it a protest or a form of protest.
I contend that the things that Facebook does as a matter of course (enabling racial discrimination, connecting hate groups, simplifying election interference, easing human trafficking, et c), which make the entire human society worse, are no more or less violent than someone making a fake bomb threat, which makes the facebook campus worse.
In both cases the action can be reduced to “sending some IP packets out of the building”.
If one is violent, then the other is as well.