I just had a look at your website - what you do is fantastic. I have been in Rio, but not in any of the favelas. My ex has had friends in the Rocinha though, so I know it is not at all like the image most people have of favelas.
The idea of taking tourists around with people who actually live in the Rocinha is great. Setting up a guesthouse there could well work. I Imagine not everyone would want to stay there, but I´m sure there´ll be enough travellers who are interested in this sort of thing.