To be honest, I have no idea who RJ is. There are just too many hints and people involved.
In my opinion the storytelling is going very fast now. In the earlier seasons every once in a while there was an episode directly connected to RJ. I like the speed and intensity and how people showing off there real faces. But still, now it seems more focused towards the BA, which somehow is connected to RJ. Reed Smith seems to know a bit but can's explain it entirely.
I am sure there will be a big finale with something no one is expecting. It will leave us with new clues, more questions and a fresh start for the hunt of RJ next season. PJ will probably team up with someone even more unexpected.
Heller is just too smart to reveal everything in the upcoming episodes. I kind of like that.
Oh man, I love this show!