That a patient with true schizophrenia can be helped with talking therapy may boggle your mind, but many cases exist (see the books I noted above and even to some extent the case you cited in the movie a beautiful mind which compound talk therapy with self therapy -which is actually involved in most talk therapy cases). Most studies show that schizophrenic behaviors, i.e. audio and visual hallucinations, delusions, suicidal tendencies, homicidal tendencies etc. are most effectively treated with BOTH pharmaceuticals and talk therapy, although often the talk therapy is ignored because of the cost. Also, one tells a true schizophrenic you are the master of your ship while medicated, and few therapists believe that talking therapy will alone deal with audio/visual hallucinations, suicidal/homicidal thoughts. Most rely heavily on medicine (some feel too much so and this is a major criticism of psychiatry today)
I agree that one would normally stress that one should be the master of their ship (IMO) after proper medical procedures have been carried out, but some stress this thoughout therapy .
You note that temporary insanity and true schizophrenia are two different arenas of medicine. True, but it is not so simple. Have you read much about the Andrea Yates case?? I have worked with many similar cases where one was really insane than and now but this does not make much difference if one wants to win a case.
As to the word idiot savant, the new terminology 'autistic savant' may be preferred now but some argue that there exist two different types of savants. The former have very low IQs and the latter can be close to normal, such as the classic Rainman story. This is my conclusion