When I said about no speaking Portuguese and experience is related to get around Rodoviaria without all the signs (just a few) in 2 languages (PT-BR and English).
Its the cheapest option, but far from the most easy, you have to deal with the transit + taxi or bus from /to hotel to Rodoviaria, getting there, search, move around etc. In Rio don't have any metro station inside / integrated with Rodoviaria, you have to get the train + bus in Estacio station.
IMO the best option is private tour or private tourist guide, of course the most expensive option.
I wouldn't recommended drive in the crazy transit in Rio (2).
And if you ask in hotel for a reliable taxi driver to spend a day in Petropolis and do the city by yourself ?
Good luck and Petropolis is a beautiful city. Don't miss the "Torrada Petropolis with hot chocolate".