I don't think Bret Stiles is the only Red John, but he is totally the brains behind the operation. My guess since the 2nd time the team went to Visualize (i cant remember the episode), I guessed it was a team effort.

I think Bret Stiles could easily be Red John, because he has that charming personality, and he also has the brains to do it. He leads Visualize, and I think that some of the people on the list of 7 (excluding McAllister, Smith, and Bertram) have been a part/are a part of visualize. We know that whoever Rj is, was a part of Visualize because of the Red Farm episode. Bret in my opinion doesn't do any of the killing (maybe the first few, but thats about it). I think that all the people involved with Rj have been a part of Visualize, because if they weren't then why introduce it anyway?

My theory is that Bret convinces the people to do the murders, its as simple as that. In S06EP02, the scene about Lisbon's Dream is useless, and that it's just another way Heller is trying to throw us off (like in S3 finale when Jane killed who he thought was Rj, but wasnt). I do think that Grace is also part of this team, but not from the beginning. In the EP03 promo, she gets married to Rigsby (the dude doesn't really look like him), this is something that will come in handy later on. I think she joined sometime before the S4 finale, where she killed Craig. I think that Craig was killed for Rj's sake. The thing that always gets me is that she has RED hair, and they are trying to catch RED John.

I think that in the Season Finale, things are going to get crazy. Rumors are that Rj is revealed on EP08, titled the "The Great Red Dragon" i believe. I think that the rest of the season will have really important people killed, some names I think of are J.J. LaRoche, atleast 4 other people on the list, one member of the team (most likely Rigsby/Grace), and also whoever Rj is.

Something I hope to happen in the finale is that Jane isnt the one to catch Rj, they lead this all up to think that Jane is the one that solves EVERYTHING, I think that Lisbon will be the one who gets Rj.