I see — that’s a pretty big problem and definitely goes far out of the scope I was trying to accomplish with my project. It would require a significant amount of time and effort because not only would you have to rebuild the entire front-end that bbPress provides, but you’d have to really get a good understanding of how the data is stored in the mySQL database and essentially build a GraphQL schema for it — and then figure out the proper way to query stuff. That is a huge task!
About your question regarding bbPress permissions — I think you could probably add a layer of authentication in your main user resolving function. Its hard to explain, but if you are using WordPress to manage users, you would have a Users GraphQL type that has a resolving function that returns things (like email, and user rights); in that resolving function, you could also extract data from the bbPress MySQL tables (I have no idea how bbPress stores this). So now, when you authenticate a user you are getting all the normal WordPress user stuff, plus their bbPress permissions as well, all within one query. It would be pretty powerful, but not trivial to set up.