In my fourth year of my PhD on schizophrenia and I'm currently writing up my thesis. I'm procrastinating right now so thought I'd do something useful with what I've been studying.
And no, schizophrenia is not multiple personality disorder.
Edit: I have to get dinner and run some errands. I'm really enjoying this so I will definitely get back and answer the rest of the questions.
Yes, the linked article already shows a good example of it. If by treatment, then it depends on what you by treatment. The sad fact is that we don't really understand the mechanisms of schizophrenia and what causes it so we don't have anything that comes close to curing it. Medications are usually just formulated to stop symptoms but end up just shutting down a lot of the brain (hence why so many patients experience non-stop brain fog and why eventually, many will hop off medication).
However, some types of treatment (for example, types of CBT treatments) try to just help patients cope with their symptoms. It's here where I think that the type of voice they hear would be important. If voices are mostly positive and accepted, it would approached differently and would probably be much easier to help than people in the US who only hear hostile voices. I really like the point in the article, how the whole conception of schizophrenia (in the West) as some horrific mental disease might contribute towards the negative voices US schizophrenia patients hear.