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.
So at least here in Australia, we don't really use categories like paranoid schizophrenia anymore (although at my lab meeting today, we were discussing whether it was useful to have these categories, since schizophrenia appearance is so heterogeneous).
For the second Q, we just call them schizophrenic. It's very rare for them to attack people. For the vast majority of cases, it's an inward problem that'll cause them to withdraw.