I am certin of one thing only.
I think that the tatto that this girl who was supposed to bug Cho's office really refers to TT group, which DOES NOT work with Red John.
Look at this more closely - RJ is too smart to send some girl to bug CBI, if he had his team of TT there all along.
So this leads to a theory, which most of you discovered, but no on said id at loud.
I think one of TT member killed this girl, and she was trying to make a clue for police, so they can find her killer. She wasnt aware that her killer was one of the police officers, also a vizualise member.
This means that either Jane got tricked by his own mental issues with cathing Red John as soons as possible, or he knows all this things but plays with us and with RJ himself to mislead him.
If i would've guessed who is RJ now - i would say its Michael Kirkland.
Watch the scene when RJ rescued PJ - he asks him "Do you know who i am? do you recognise me?" Bob Kirkland asks same thing. Maybe he dont want to let in his mind the thought of his brother being RJ.. I dont know.
But still, Patrridge theories seems plausable, but also a little bit far-fetched. If RJ doesnt work with TT, it would be a problem for him to fake his death. Either way, if RJ faked his death multiple times before, he would gone off with this without anyone noticing.
I think its a little bit too confusing, but Heller knows what he's doing.

So summing:
*RJ doesnt work for TT
*TT hired this girl to bug Cho's office
*RJ is either Partridge or Michael Kirkland

What do you think?
(sorry about my bad english - im from Poland and its my first post here)
Hope you enjoy real answer for RJs identity!