Hello ftanired!
I am brazilian too!
1 - If you have a civil wedding or a religious wedding with civil effect in Brazil, it will be valid in Canada as well. The other way around (marrying in Canada) would be different and you would have to legalize it over there (go to the brazilian Consulate, and with the certificate they issue, register it in a "Cartório do Primeiro Ofício" in Brazil), but it has nothing to do with sponsorship, etc.

I have tried to register my marriage in Canada and all the answers I got from both Consulate (in Brazil) and Vital Statistics (in BC) is that the marriage is already valid.
2 - Assuming you are applying outland via São Paulo, everything in portuguese can be sent just the way it is, with no translation to english or french. There is no need for translations as long as it is in english, french, or portuguese. It is at the top of "Appendix A / Document Checklist - Immigrant". Send a copy ("cópia autenticada") of the marriage certificate.
3 - If she has ties with Brazil (job, school, etc), she can apply for a tourist visa and get approved with no problems. But I had absolutely no ties with Brazil and had my tourist visa approved (with no interview), to stay with my husband in Canada and apply for sponsorship (outland).