I feel that Ron is RJ, he is from the first season and In recent episodes he appears very often (I would say unnecessarily). Not to mention the various clues, such as the fact that he had the phone in hand when RJ called PJ etc etc: there are several posts about it, needless to mention all over again.
Ron is not on the list:
The "list" is one that has Patrick on his little notebook. 7 Those are only the characters more suspects, but this does not exclude all others.
Sorry for my english, Google Translate made this.
Malerio.