How about a new law:
Currently, you have the right to play dangerous sports; to race formula one, scuba-dive, climb Yosemite rock walls, sky-surf, etc. etc.
Currently you are supposed to have the right to freedom of Religion. Thomas Kuhn, in his work about 'paradigms' and the religious nature of paradigm-changes in science; seems to support your idea that even physics can be regaqrded as a religion.
How much more then, can the social sciences be regarded as being religions.
Although there are many religions and cults out there who would like to 'save' you according to their beliefs; you are supposed to have the right to reject their evangelical concerns and say "I don't believe in that".
Now, a religion might say that they are terribly concerned about your unbelief and that they really know its best for you to be 'saved', for example: 'saved' by David Koresh of Waco fame; but you are supposed to be able to go your own way.
Now, why not have a law which allows you to have a "living will", where you decide in advance what can and can not be done about you in certain kinds of alleged social disturbances?
For example if at some time in the future you are in a social situation where claims are made that your behaviour is dangerous to yourself and/or to society, and claims are made that you are deranged. Your 'living will' would set out how you should be dealt with. It could state for example, that you are not to be 'saved' by David Koresh's current equivalents. It could state that you are not to be subjected to short doses of excruciating pain (one of the methods psychiatrists have dreamed up in their bid to coerce changes in behaviour).
Your 'living will' could state eg. that in the event of your claiming ownership and responsibility for your actions, you are to be held responsible for them and have the right to face charges of law-breaking and go to jail rather than have some pscho-theory imposed on you.
Your "living will" could state that all objections and charges relating to your behaviour be made explicit; that you be charged if breaking the law; if you are considered dangerous then the issues be dealt with in a non-pscho-theory technical legal manner involving dispute-mediation; etc. You could thus apply your present beliefs to protecting yourself from being in future coerced by others beliefs; you could ban electro-shock, psychological examination, drugging, medicalisation of behaviour, etc. from ever being done to you.
Now, the terribly concerned evangelical pshyiatrists, or David Koresh's followers, or who-ever; might oppose this new law by saying you can not be allowed to take the "risk" of making the "wrong" choice about your future.
But just a minute: you are allowed to risk your life right now by doing dangerous sports. So you have every right to be entitled to a "living will" of your choosing, regardless what "risks" some self-appointed would-be "saviour" thinks you are taking. No one has the right to patronise you!
Regarding your practical concerns:
People with neurological illnesses are not stripped of rights as people with so-called mental illnesses are. Further, the term "mental ilness" is non-sensical- the word "mind" does not refer to a physical object. If one means "brain illness", this is the term that should always be used.
But that places psychiatry in a problem; because they are unable to prove their alleged illnesses actually are brain illnesses. And a speculated brain illness is only speculation.
The "labelling" process re: so-called mental illnesses has been described as ritualistic and ceremonial in character- the official condemnation of the heretic by the psychiatric high priest.
Re: your practical comments:
That is commendable to seek out those who refuse to carry out this "diagnosis" ritual. Dialogue is much better than "diagnosis" (and these "diagnosises" are no more medical than alleging that someone is "un-American"). It has been said that the willingness to listen to someone and to try to understand them and to disagree with them without humiliating them, is a skill becoming rarer by the day, especially among psychiatrists. Forcibly denying someone the right of personal moral agency, is a grave violation of the person.
If there are personal circumstances in some individuals, that may or may not contain some as yet not-discovered neurological curiosity; but that severely restrict their social functioning; I don't see why insurance coverage can not be designed to cover this based on sound pragmatic evidence with no psychiatric component needed. If someone is disabled for whatever reason you don't need psychiatry to figure that out.
I think what is needed is a new profession and a new kind of professional. A profession of high-quality "listeners" who people can see, such that they can be encouraged to self-educate themselves about themselves and assume more control over their lives. And such professonals would never coerce; but instead have a contractual relationship with those that sought their services. See the book "The Ethics Of Psychoanalysis" by Thomas Szasz for positive ideas on how to deal with these issues.
Any social control issues must be separately adressed by mediators etc.; and categorised under "dispute resolution" and "policing"; and must not be confused with the other issues. And freedom of religion and freedom to choose or reject the theoretical fashions of the day must be maintained.
Can you see the benefits of a NO-pschological-monopoly approach; with "living wills" and a new profession who help people understand themselves using ethical contract, without coercion?