Maybe I'm "absolutely insane" but I don't see how what you wrote proves, or even demonstrates, that schizophrenia is a disease. The whole point is that disease/illness is a paradigm used to understand a collection of behaviors which people suffer from. This paradigm usually involves some kind of pathogen attacking bodily functions. Pharmacology can be used to destroy the pathogens and treat the disease. With mental "illness" this is untrue. Rather we believe that the brain is largely chemical, and that current "illnesses" result from non-harmonious interactions of these brain process. With chemicals we can correct the bad processes, or supplement processes that aren't firing.
But why call it a disease at all? We could equally look at mental illness more like, say injury. When my ankle is broken, some amount of drugs may ease pain, or possible reduce damage caused by swelling, but no drugs can heal it, because there is no pathogen to be killed. I am not suffering from "cantwalkitis", even if supply of opiates reduces much of my suffering and allows me to hobble along and ignore the pain. The best way to fix the problem is to repair it manually (not an option with the brain I know). Indeed, perhaps mental health problems are caused by psychological "injuries", sometimes the bodies own mental processes may exacerbate these "injuries".
I know one of the problem of those who criticize models is not supplying their own, which is why I tried my "mental injury" model above as a contrast, but I'm not a psychologist or neuroscientist. Perhaps my model is equally lacking? Someone with more knowledge and insight than me can propose a better one. However, even I can see the theoretical limitations of the mental illness paradigm of disease. As I've said "Where are the pathogens?", but there are equally compelling questions about contagion (almost all diseases are, no mental "diseases" are), or the difference between disease and condition (which exists for physical ailments but not mental ones). The disease model doesn't just allow for us to diagnose something bad and supply drugs to stop it. It also explains various other phenomena, cause, spread, contagion. The model was developed to deal with real world phenomena around diseases, ones that simply do not exist for mental "diseases".
I understand the appeal of the disease paradigm, which has had great explanatory power for dealing with pathogen induced illnesses. I also understand the desire to remove responsibility for actions that are beyond persons control, which is one reason we moved from the possession model of mental health to the disease model. I am also not claiming that people who suffer from mental "illnesses" aren't really suffering, from real phenomena beyond their control. The question is does the current model put our knowledge in a conceptual schema that aids us understanding and helping those who suffer. I feel the disease model has gotten us as far as is possible, given theoretical limitations