Re: causing no (serious) harm
I heard a story about what "Fuji" means. I'm told that the etymology of the character "fu" as in Mount Fuji basically means "2" as in futatsu, but really more like 2 opposites (yin and yang). I'm told that there are many examples of putting "fu" in front of things to make the meaning become "opposite" read as "not". The "ji" of "Fuji" also means "2". So the idea is that when you look at Mt. Fuji you see one side, and you know there must be another side (that you cannot see) - but the word means "not 2" - as in there are not two sides, only one mountain.
In aikido, there are not 2 people (uke and nage), but only one reconciled unit.
My opinion, is that working towards doing the "minimum damage" required to stay safe as the attackers become more sophisticated, more dramatic and intense, less concerned for their own safety, and as the number of attackers increases approaches this ideal in the most practical way to approach the ideal of purifying our will to violence.
It forces you to need to start figuring out how to reconcile the opposites of self and other - to have some degree of integrity with these principles when being pressed hard by your attacker(s).
This kind of approach, to me, has led me to the understanding that I need to continue to not buy into the delusion of separation (on the vertical plane). I must continue to move such in such a way to set up the circumstances that continue to draw/lead energy out of the uke primarily (and not into me in a destructive way of course) so that we can reconcile in a physical way. Normally, I see people in aikido misunderstanding this kind of thing (IMO!) where they end up just doing some kind of evasive movement and then they crank the uke from superior position. I don' t mean that low level nonsense. I mean, lead them out and unify (reconcile self and other) so that we both are contributing to the overall movement so it cannot be countered. Doing "minimal damage" lead me to that kokyu of social-coordination approach (instead of concentrating _only_ on the kokyu of self-coordination which I find to be interesting but obviously not the goal of aikido or we would all be doing Chen style tai chi or something!).
Finding efficacy within the bounds of do minimal harm and constantly refining towards being able to safely and effectively do even less harm with the same attack - then increasing the level of the attacks removes many of the mundane delusions like directly pushing, pulling, lifting, cranking/paining/threatening the uke, etc. I agree that it can only be done from a place where you have the choice to be lethal.