A few random observations.

Something bothers me about the scene in Jane's living room.  Haffner knew it was about RJ.  Yet, when PJ said so, he said he was leaving.  Why?  If it's him, perhaps the others don't know his identity, even though my bet is on McAllister.  Still, it doesn't make sense.

I do believe RJ is trying to kill off the other 6 on PJ's list.  For what purpose?

One thing that narrows it down for me is that the actor playing the Young Man bears a strong resemblance to Haffner and McAllister.

Another clue I believe we've been feed concerns coffee.  Smith likes his with cream and sugar and Haffner, black.  Anyone else know about the others and how this might tie in?  It was certainly done on purpose.  (I am hesitant to say this, but Carmen Lee can be an anagram for 'lean creme'  -- makes me either think coffee or uniform).

Does anyone else think that perhaps Roy Tagliaferro might be a disciple of RJ, as well as Jay Roth?  Or must they be RJ?

I previously mentioned the song MacArthur Park, Lisbon's 'happy memory'.  SPOILER: we know Jane kills PJ in a park.  We know the song is a metaphor about a relationship that is crumbling, that took a lot of time to build ("the cake out in the rain").  I think it alludes to the demise of RJ, because in the TV guide it is stated that RJ wants a relationship with Patrick.  Not all of the suspects do.

Well, those are my random thoughts. Hopefully, there will be answers soon!