You only need a tax id number, known in Brazil as CPF (Cadastro de Pessoa Fisica) for individuals or CNPJ (Cadastro Nacional de Pessoas Jurídicas) for corporations.
You only need a passport and a birth certificate.
To open bank accounts, open corporations, create credit history, file income tax, etc.
Yes, but only if you have a CPF and legal residency in Brazil (permanent visa). Only a few foreigners managed to open and maintain bank accounts in Brazil while living abroad.
Not necessarily, only if you have assets in Brazil or make a certain amount of money per year.
Yes, by Law an attorney is required to sign off the Articles of Incorporation.
No, real estate bought in the past by you, as an individual, does not qualify you for the investment visa; prior registration is required before transferring the money to Brazil.
Yes, you can marry and also divorce via power of attorney, without even being in Brazil.
Yes, foreign companies can operate and own assets in Brazil.
