No one here can diagnose whether or not you have schizophrenia. Only a qualified, experienced psychiatrist can do that. And if you have schizophrenia, you very probably need medical help because it can get worse with time, if left untreated.
(2) The diagnostic criteria for schizophrenia seem incoherent and lacking in empirical content. Prostate cancer, OTOH, is an uncontroversially real condition with clear cut symptoms and diagnosis.
(3) Being labelled with a mental disorder can be a huge stigma that you have to deal with for the rest of your life. It might affect, for example, your job prospects and your parenting propects. (People are learning in the UK that new mothers are unwise to admit feeling depressed to medical staff.)
(3) Everybody has voices or at least one voice in their heads. It is just that only a few people such as the poster and Richard Feynman have the necessary self-awareness and intellectual integrity to talk about them openly.
As Eckhart Tolle might say, the real question is whether one identifies with the chattering voice. People who are completely identified don't perceive it as an external entity, but it is still there: they are the voice.
(4) Such voices are thoughts, and many of our thoughts are random and contradictory. When we daydream (or dream at night) they are connected only by loose associations. Nobody really has control of their thoughts. Try drinking 6 cups of coffee after a 24 hour fast and watch the cascade begin!
(5) By listening to our thoughts and becoming more aware of them we remain in control of our actions. Just because we have a particular thought, it doesn't follow we must enact it. The psychiatric profession is all about regulating people's behaviour for social reasons.
As someone with a close family member who is schizophrenic and has spent a lot of his life refusing treatment, I think it is inadvisable in the extreme to deliberately avoid recognizing the condition, to minimize or trivalize it, and deliberately avoid seeking help for it. The kind of voices the poster describes do not seem to match the kind of stray thoughts that most people have.
As an adult, unless you pose an acute danger to yourself or others (which this fellow gives no indication of being), nobody can force you into treatment or medication that you do not want to take. The least he should do is learn about the condition, find out from a professional whether or not it actually applies to him at all, and his options if it does.
While psychiatry certainly does have its shortcomings, I have not seen a lot of good come from the Scientology anti-psychiatry approach, or trying to deal with problems of this magnitude (potential schizophrenia) on a pure self-help basis.
More info is available here: http://www.schizophrenia.com/diag.php
No one here can diagnose whether or not you have schizophrenia. Only a qualified, experienced psychiatrist can do that. And if you have schizophrenia, you very probably need medical help because it can get worse with time, if left untreated.