Nice stuff. But as a brazilian myself i think it's important to note that Maracanã is just one Soccer Stadium. If you really want to make soccer stadiums as UB i suggest calling them that or Estádio de Futebol (which is portuguese for the same thing).
I'll not lie that the references to Carnaval as a UA and Soccer Stadiums as UB are sort of an stereotype. I was thinking about modding Brazil in too and maybe have a UA related to the fertilily and agricultural power of Brazil, my initial idea was having connected food resources yielding more than normal.
BTW, i loved the idea of the Expeditionary Force as UU (You might call them Pracinhas, a more popular name, if you want), my initial ideas were having the Fatherland Volunteer Corps (Voluntários da Pátria) from the War of The Triple Alliance but i think your choice is fine too.
About the UB, i think it's hard to think about something that really represent the whole nation, but i'm sure another brazilian forum member will end up coming with an idea.
I find the worker idea quite strange.in my mod I picked up the Voluntarios (I called them Country Volunteer, but Volunteer Corp would be fine) as the UU, and my other UU was supposed to be a new worker that could build farms much faster (with the right policies it could even become an instant farm), but I haven't managed to add the new worker yet.
but keeping the Republic theme, I think that the Exp. Force is fine. for the UB (or another UU) I would pick something else, but if I had trouble deciding for the imperial era, I imagine that choosing one for the republican era is even more difficult.
the problem with UU and UB and traits is that in Civ5 there are basically no negative stuff. one really ludicrous UA could basically invert maintenance for profit (which could be representing corruption, but I dunno you'd make that work), but increase unhappiness. the only problem is that here in Brazil we're unhappy but do not do anything about that (we keep electing the same corrupt people)![]()
you could also try to get an UA to work (or UB with certain requirements) similar to what's happening now in Brazil, where the government basically sustain the poor in the poorest areas of the country (where there's no agriculture or industry)
I really like Semprini's version. I'm still not happy about how it all resolves around soccer. My country is much more than this. But it seems to be an incredible mod.