Use of Force

By "force", I here mean in a way that violates personal boundaries.  This could tie into a broader topic: what violations of boundaries (whether those preferences are stated explicitly or implicitly, or plausibly guessed) can be justified, and when?  I'll be looking at that question, but I probably won't consider all possible preferences and boundaries.  I'll probably mostly consider the acts of "force" which are typically considered violence.
==What use of force?==
Here are some different kinds of force, some are less severe and easier to justify, some are more severe and would require more dire circumstances, and some might be nearly impossible to justify under any circumstances:
*grabbing, pushing, pulling
*forceful separation, restraint, escorting away, imprisonment, banishment
*shoving, throwing
*collision, punch, kick, body slam, etc.
*wounding
*killing
Other activities which may not involve physical force, but seem conceptually related (they are strongly contrary to people's wishes/boundaries, peace of mind, and can conceivably lead to physical violence), I'm not sure where else to put them for now:
*doxxing
*harassment
*intimidation, threats
==When to use force?==
When is some force justified?  Usually, I'd say it is when there is a goal you must accomplish, but there is a conflict, and none of the other options are going to work.  For those other options, see The Main Options in Human Conflict.
I find that many people often consider "changing minds" and "use of force" to be the only options, completely ignoring the option to separate, or perhaps seeing separation as ineffective at preventing violence they see as inevitable.
"Self defense" is fairly uncontroversial, especially in an urgent situation to prevent immediate danger to yourself or other people.  A "self defense" justification becomes less clear in situations of pre-emptive defense.  More will need to be said on that.
Right now this a big deal with the punching nazis thing.  Minor domestic terrorism against some people (nazis)?  What about bombing terrorists who are among civilians?  What about using force on North Korea?  Scamming unethical rich people out of their money? Or holding one of their kittens for ransom if you're desperately poor? What about spanking children who run into the street? What if someone is filming you protest, and you fear they will use that footage to send harassers after you or something?