I do NOT think it is likely that PJ is RJ, BUT there have been 2 episodes where we have been able to hear RJ speak... And let's be real people - RJ's voice is sooo obviously PJ's (simon baker) voice.
Although, that is a minor and maybe even an insignificant thing to add, it all just leaves me a bit puzzled. But I bet that's the intention ? 

I still find the RJ murder symbol very interesting.. what exactly does the smiley face made up of blood convey ? What does that represent ? What is the story/meaning behind it ? What is the message ? I think this could be a massive tool to figure out who RJ is.

And is it just me, or does NONE of the 7 people on the list seem like they could be THE RED JOHN..?!? I would imagine Red John to be like a twisted/demented/disturbed version of PJ. Idk if any of those 7 seem to be only PJ's level... maybe Stiles of visualise, but he has a distinctive BRITISH voice..lol.
Maybe PJ has an evil twin or something haha. 

we know this:
RJ definitely has a position of power and lots and lots of connections
RJ definitely has this sort of sick / obsessive interest in PJ

Ughhh i cant wait to find out who red john is!!!!!!! :D