Yes if you sell outside from the country where the company is registered. But it remains possible from UK company to UK consumer. Or a french company to a french consumer. If not you can use MOSS.
The people I know who have obtained NHR status were European citizens. For a Brazilian national, you first need to obtain a resident visa in Portugal. NHR status itself is fairly easy to obtain, whatever the nationality of the applicant.
Brazilian citizens can apply for NHR status in Portugal, but NHR status is only for residence in Portugal. Not in any other member state of the European Union. If you leave Portugal for another Member State, you will lose the benefit of the NHR.
For Estonian OÜ keep in mind that changes in your company such as shareholders or directors must be notarized in your country and then in Estonia. You cannot do everything with the e-resident card.