With respect, I disagree with your statements.
I was taught that the more skill one has, the less harm one should have to do.
As an ethical belief, that's fine.
One of my students was brought in to see the Chief of Police after executing an arrest in which the suspect was put in the hospital. The Chief complimented him on his martial arts prowess, and told him that he was probably the best tactical fighter on the force. He followed that with, "If you're really that good, why do you have to hurt people." It was a good lesson for him, one I had preached many times. But from the Chief...
A police officer has obligations that ordinary citizens do not, including the general obligation to use the minimum amount of force required to affect an arrest. That is partially because police officers are required to put their lives in jeopardy as part of their job description.
I do not think such advice is applicable to, or wise, for an ordinary citizen.
Morihei Ueshiba developed aikido (the way of harmony) as the highest expression of his art. Mitose stated that true self defense was to escape a situation with no physical contact between opponents.
I agree, and I believe that self-defense begins with situational awareness, and includes simple expedients like removing yourself from dangerous situations before they become dangerous to you, if you can. Running away works too, if that avenue is open to you. It's all 'self-defense'.
The primary directive of self-defense is just that - self defense. If you can back away from a challenge or a fight and avoid it altogether, that is a much safer alternative than engaging in a fight, even if you are confident of victory.
However, if you cannot avoid violence, then again, the first and only rule is to defend yourself. Nothing else matters.
A higher level of skill should allow you some room to operate and to make some choices. It may be necessary to move up and down the force continuum as the situation unfolds. Aside from the physical skill necessary to do what needs to be done, there is skill involved in choosing the appropriate solution to the situation at hand, and skill at being able to adjust it.
If you are talking about sparring or kumite, then I agree.
If you are talking about self-defense, I could not disagree more.
First - self-defense is a life-or-death struggle. You have no assurance that if you lose, you will live. You must assume that if you lose, you die.
Second - if you are indeed fighting for your life, there is no 'situation' to allow to unfold. You goal must be to end the confrontation as quickly as possible, because every blow you trade, every second you are still struggling, is another step closer to your own death.
Third - again, if you are indeed fighting for your life, your assailant is not holding back. They are using everything they have, and they are fully determined to kill you using any means necessary. If they have a knife, they will use it. If they have a gun, they will use it. If they have not used it yet, it is because they prefer not to unless they should begin to lose, then they will. Every moment you delay ending the fight, they have another opportunity to use that hidden weapon on you and kill you.
Fourth - you may well know your own skill, but you do not know your attacker's. He may be evenly matched with you, he may be better. Or he may be stronger, faster, more experienced, flat-out lucky, or just immune to pain due to drugs, etc. Your careful escalation may quickly result in your own overmatching with a singe decisive blow against you.
Fifth - the mind boggles at the potential plight of the poor student, who knows a variety of techniques and is trying to sort through them in search of the least lethal whilst being pummeled.
It is my opinion that real skill comes from assessing a situation correctly in a split second, and effecting a positive defensive solution using the minimum amount of destruction necessary.
That may indeed be "real skill." If it is, you can have it. I will inartfully and inelegantly bash in an attacker's head with a brick, if one happens to be handy.
That includes recognizing the danger ahead of time and avoiding it. It also includes adjusting my response based on the intent of the attacker, the skill of the attacker, other individuals who may be harmed by a possible wrong decision on my part, legalities, etc.
I do not care what the attacker's intent is. I'm under attack. I will assume he intends to kill me. I will also assume his skill is greater than mine, so I will use everything I have to defeat him. I will attempt to avoid harming others only in the sense that I always aim center mass. As to legalities, I would presume that I am fighting only because I have been attacked and I am reasonably in fear of my life. I can think of no other reason I'd be fighting. If so, I have no fear of legal consequences. My life is my first priority, the rest can wait.
There is responsibility with skill.
When self-defense is involved, I think the biggest responsibility that martial arts skills teaches is that fights can often be avoided, and should. Knowing that many of us are skilled in ending human lives should also teach us not to take human life casually. These, I agree with.
Once the need to defend one's life is upon them, I think the only responsibility is to survive. How that is done is really of no consequence.