Some things here are makes you think twice.
Red John is a powerful person well connected and with loyal minions who are not naive miserable persons and still they all talk about him with admiration like some kind of a deity.

So how some clown can become so powerful more powerful then some billionaires or high state officials.Brett Stiles is a clue but not necessary the RJ himself, maybe father or he do something bad to RJ family so he protect him now and paying his debt.
Anyway I believe that RJ had a bigger reason to kill Jane's family maybe revenge or who knows what.

RJ is womanizer and powerful man and only people like that could control and impress beautiful and strong person like Lorelei.So i would put my money on Mashburn. .
I see RJ as modern professor Moriarty on his mission.