The definitions you included (thanks), seem to boil down to what I said: they feel they're in the wrong body.
Not all of them do, but we can focus on the ones who do for now, as I said.
Because feeling you're in the wrong body isn't life threatening.
It can be, and I have already posted a study concluding that suicide rates among trans people are higher when they're denied gender-affirming care.
Also, not all conditions for which minors sometimes get irreversible or complicated treatments or surgeries are life-threatening either. Those conditions could have extremely drastic effects on minors' health, however.
Again, I'm not opposed to counseling. I understand that many young people are depressed or even suicidal. I'm not saying "do nothing".
Now, one of your citations included the phrase: "sex to which they were assigned at birth." Are you of the opinion that a person's sex is malleable?
Surgery and hormones can change sex to a large extent, although they're definitely not a perfect match for being born a certain sex. Still, medical professionals recommend sex reassignment surgery to a lot of trans people (but rarely to minors, as the link I posted has clarified) as part of treating gender dysphoria.
So I'd like to hear YOUR definition.
There's no such thing as "my definition." This isn't some matter of opinion or personal preference, and I'm not a qualified medical expert either. Offering "my definition" here would be like a layperson's offering "their definition" of evolution or anxiety even though both have highly specific definitions offered by experts, based on decades of research.
I think it's compassionate to call it a disorder. I suspect it will ultimately be categorized as a mental disorder.
Calling it a disorder is more harmful than not nowadays because 1) this isn't how any medical organization classifies it, so it's simply incorrect given current evidence, and 2) classifying it as such is a common way of dismissing the necessity of gender-affirming care, instead proposing any of a multitude of unevidenced and ideologically slanted "treatments" in lieu of proper approaches.
I have seen a lot of trans people wish that there were a non-surgical treatment for their specific condition. If the treatment were as direct as getting therapy and calling it a day, many trans people's lives would be much easier, but that's not the case.
I think that as things stand, there's no justification to call it a "disorder," and even if we did call it that (despite the fact that no medical organization would agree), that wouldn't change the current medically approved treatments for gender dysphoria. Just because some people, including a lot of ideologues and politicians, want medical evidence to be different doesn't mean it can just change overnight.
If enough evidence accumulated and medical experts classified it as a disorder, while offering treatments in that light, then hopefully that would benefit trans people and make treatment more effective. That scenario hasn't happened so far, though.
Are you of the opinion that the medical industry - rife with corruption as it is - is somehow not seeing trans as a money making opportunity? Like this is the one topic on which the medical profession is morally and ethically upstanding?
Hold on: now we've moved on to conspiracy theories about the medical industry in an attempt to discredit their established positions? I think the similarity between the above and anti-vax arguments is conspicuous.
"The medical profession" is not some monolithic entity; there are major medical organizations across the globe and millions of medical professionals worldwide who run the gamut from morally and ethically upstanding to corrupt and unreliable. The idea that the vast collection of medical bodies and professionals would somehow agree to concoct a plan to milk money out of trans people is both unevidenced and well within the territory of unfounded conspiracy theories.
There are also numerous ways the medical industry could make money from trans people other than surgery and gender-affirming care if they were really aiming to maximize that without any regard for medical effectiveness. For example, if medical organizations came out tomorrow and announced that some ultra-expensive medication were now approved for "treatment of gender dysphoria," I think it would almost surely sell like hotcakes, especially because, as I said above, many trans people do wish they could avoid the hassle of surgery and the lack of access to gender-affirming care where they live (whether in some states of the US or in other countries altogether).
There's also the fact that any effective treatment is bound to generate a lot of money, so the same conspiracy theory could be circulated about aspirin, paracetamol, vaccines (and that has already happened, as I'm sure you know), and all other effective treatments that generate a lot of revenue. Just because a treatment makes money doesn't imply sinister motivations behind it or ineffectiveness thereof.
So again, I'd like to hear YOUR definition,
See above. I've already addressed this.
and not make arguments from (questionable) authority.
All authorities on the planet, being human and fallible, are questionable to varying extents. This is not a sufficient reason to dismiss what they have to say on a topic related to their expertise unless one has significant evidence and proper qualifications, and it doesn't automatically mean that all or even most of their positions are incorrect.
An appeal to authority is a fallacy when the authority is unjustified, not when the authority's position is both qualified and corroborated by other reputable and relevant expert organizations from around the world. Peer review is a core pillar of science, and it is why Stephen Jay Gould's peer-reviewed positions on evolution should be taken more seriously than those of Ken Ham or some random preacher.
Again, the similarity between the above line of reasoning and anti-vax arguments is glaring.