Yes

No, parkinson's affects the dopaminergic neurons of the substantia nigra, which is part of the mid-brain.

Michael Bryan Goldberg has written:

'Dopaminergic effects on intraocular pressure and binding in the cileary processes'

Typically, the temporal lobe and limbic system are involved in schizophrenia. Lesions, malformations, or simply dysfunction in dopaminergic neurons of these areas of the brain can result in the positive and negative symptoms of schizophrenia.

Since excess dopaminergic activity is indicative of schizophrenia, antipsychotic drugs that block dopamine receptors are the usual treatment for this illness.

No. It is a neurologic disease, originating in the dopaminergic pathways of the brain, including the substantia nigra, caudate and putamen, as well as other structures.