I spent four years in Rio Comprido/Tijuca and left when I was six, Rua Conselheiro Barros near Rua do Bispo, not quite the favela there. I lived in various other places in Brazil too and got to visit and stay in many of "sketchy" places because of my parents' work.
we probably walked around the same areas of Rio Comprido, I used to take the bus down from Paula Ramos to go to the grocery store and ATM every week or take the bus to the lagoa for jogging. I think most of Rio Comprido is safe, there is bandits but they go to copa to rob people im sure