please open your minds to some realities here:

1- there is no f..... way they would show us RJ in the promo. Forget about Mc Allister.

2- Brett is dead. If he is not, then Cho is a total idiot not to check his face (if he didn't) and Heller is playing cheap tricks.

3- the person who jane killed (or not) in the church is:

    a-) bertram: patrick says "now you're asking for mercy after all you've done?" First of all, RJ doesn't beg for mercy otherwise the whole RJ character design goes to trash. Secondly, if it was RJ he was shooting in the church, PJ would have said something more specific than ".... all you've done (something like "did you show mercy before killing my baby or something") meaning what he did being a TT guy and his attempt to kill PJ (which is failed) and the bartender (which is succeeded).

    b-) Barlow: I don't have a specific reason but he is connected to RJ and might show up at such a sequence because he clearly has a grudge against Jane clan. Maybe he's one of the supporters of RJ and Barlow is facing PJ as an introductory reveal (plus his voice may match with the guy in the church when spoken out loud. Check it on youtube, you'll find it).

    c-) Judge Manchester: He might be the head of TT which puts him in a position to say "It's over, I've won. You're trapped here or sorts. Plus, having 1-2 scenes in total at the show doesn't make him either Waldo or Kaiser Soze. By the way, his voice resembles to the church guy too. But the thing is, the guy in the church is not RJ. 

4- Clearly some other person (either Stiles or Sheriff) has survived the blast but being Red John is another thing. He might just be trying to save his ass just like Bertram is.

5- Even though I kinda like theories about Bob/Mike Kirkland duality, there's no such a solid theory posted to keep all ends clear so far.

6- Zombie Bosco theories are really creepy but we have seen him shot to death, plus his body afterwards.

7- CBI Ron is the only one who we can identify as Waldo or Kaiser Soze but I doubt that he can pull off the RJ character unless he has some great acting talent which we have never seen so far. (The guy turned out to be Kaiser Soze in Usual Suspects was also great playing the crippled guy). If I had seen that acting light in this guy, I would bet on noone else because as an actor, he doesn't have a bright past and he can totally be flattered with being revealed as RJ (as the undisclosed actor has shared his feelings this way) plus the other things above. Plus, having a round beard DOES help conceal your face to be easily readable / fully characteristic.

8- Stiles being RJ would be a total insult to us as the audience. Everyone knows that including Heller.

9- Dr. Linus is supposed to be in prison and we'd have heard if he broke out or was released.

10- PJ is supposed to kill RJ at the park not in the church. This is a known fact. 

After all, what do I have in hand? Almost nothing. I am no different than I was at the end of S01E01. Nevertheless, keep an eye on what I say above...