Flaws:

Early on in the film we see Nash's roomate. Later on we see an agent that tells him about his role in fighting communism. It is hinted that these characters are figments of his imagiunation. (Hallucinations related to schizophrenia are more auditory).

The figments start off being helpful. And later on they give him difficultys.

Not all hallucinations are persecuting; but to show them as a some what imaginary friend may confuse schizophrenia with multiple personality disorders.

Overall the movie hardly covers what schizophrenia really is. I wouldnt suggest this movie to learn about schizophrenia.