What is it like for an Australian to live and work in Brazil?

Question

I have qualifications to teach English and by the time I plan to go I would also have an arts degree. I have friends there too in Recife and Sao Paulo. Is it a safe place? I have heard there is poverty and as a result pick pocketers and people stealing etc. Would I be able to go out by myself at night or even during the day? Has anyone else ever taught english there or just gone for a year or so? I don't speak Portuguese but am guessing I would pick it up, or should I learn it first? There are a lot of questions there sorry but any input would be appriciated! Thanks