I’m not an expert translator and actually am not even an expert in the language. I started the job because there was nothing done. I agree with the issues you raised about doing the translation directly from English. In fact it is better. I was not really concerned with high-quality results, because I was too hasty. But I agree that the ultimate goal should be to get high quality results.
In the spirit of the open-source community that is going to evolve the code over time, with the view that everything can be improved.
The questions that you put on “Flag” really caused me any questions at the beginning and at the end I opted “Sinalizar”, but I agree that “Alertar” is the best option.
Another question that occurred to me was in regard to “Bookmark”, I ended up translating as “Adicionar Marcador”, but perhaps not the best option. In web browsers, Bookmarks has been translated as “Favoritos” or “Marcadores”, but in Discourse bookmarks and favorites are two different things.
A workflow that allows us to start from English and at the same time take advantage of what has been done from European Portuguese can be obtained using Transifex.
There you could mark all translations as “Not Reviewed”, and as you go translating from English you mark as Reviewed.
I can continue getting the translations from Transifex and committing, from time to time, as you get advancing in translation.
I added you in Transifex project Discourse-PT-BR
We can work in this way? What do you think?