Not all violence is murder. But intentionally killing a person when it's not necessary for protection is exactly what murder means, at least in an ethical sense.
All use of mind control violates the will of another sentient being. One can construct a hypothetical in which it is necessary to prevent a greater (or simply more personally urgent) evil, but violating a person’s most fundamental being is vastly more similar to using sexual violation and torture to get what you want than it is to nearly any other form of violence.
Why is learning to mind control inherently more evil than learning to kill? Presumably, you don't have to actually mind control anyone to learn a mind control spell, any more than you need to own a magic item to learn Identify. Even if you do, there's no reason it couldn't be a volunteer (perhaps a fellow apprentice) who has consented to being charmed in return for practicing their spells on you.
I don’t beleive that a person could learn how to violate the minds, the conscious will, of others sentient beings, without catastrophic trauma to their own conscience and self-identity. For a person to willingly learn that…skill set, would require them to not view other sentient beings as people with a right to live and act of thier own accord.
Learning to fight requires nothing more than being willing to fight if you have to, to enjoy physical contest and challenge, or even just to want to be in shape.
The two are so wildly different on every level that I’m always a bit…I don’t know the right word here. It’s like having people seriously claim that the air is water and I’m actually a hallucinating fish, and trying to explain why that isn’t the case.
I would take it a step further and argue that all violence is a violation of self. It's simply that we say its acceptable in certain cases (self defense) but not in others (punching your neighbor because you felt like it).
We can dismiss out of hand your first claim, simply by looking at any example of consensual violence.
Violence is also quite often not especially lasting in impact. I’ve fought more neo-nazis and other white supremacists than most folks have, I reckon, but I never put anyone in the hospital, much less killed anyone.
I would yeet myself out of this mortal coil before I’d allow someone to mind-violate a neo-nazi to force them to change their thinking. Kicking thier ass to teach them to stay away from my friend’s bar or stop hitting on my other friend’s teenage sister is an act of Good. The other thing would be detestable evil worthy of the strongest legal punishment allowable by the laws of my country.
In terms of learning the magic, I think there's an important distinction in that combat spells can be learned with the intent of using them against non-sapient threats, while most charm spells can't. That said, in the real world, we have plenty of people trained with weapon systems that are only useful against humans, and we don't call such people (soldiers) automatically evil.
Depends on who you ask, but sure. Most of us don’t label soldiers evil. Of course, if they were also the people starting the wars, we would.
Likewise, if we had a world where mind control was used by every army, I’d only consider the leaders necessarily evil, whereas the soldiers would generally be a matter of personal action. So, I don’t think the soldier example really tracks.
Additionally, if Charm Person were evil simply because it only targets sentient targets, then Hold Person should also be considered evil (because it only targets humanoids, which are almost invariably sentient).
Certainly, Hold Person is capable of being used for reprehensible ends. On the other hand, a LG sheriff who utilizes it to capture criminals without resorting to violence is almost certainly not endangering their alignment by using Hold Person (or Charm Person, for that matter) IMO.
You really think those two things are the same? You really think that “used only against sentient beings” is anyone’s problem with mind control?