I've no idea who red john is as I think the creators still haven't decided.
One thing I was thinking was can we even be sure that it was even the real red john in the mask at the end of s2E23 it may well have been Timothy Carter again acting on his behalf & not the true red john as many think.
Which pretty much shows that they can at any time say actually who you thought was red john was actually someone acting on his behalf & until we really get much more concrete evidence & scenes with an undeniable "true" red john, in which it can't be denied it was really him, it's pointless making a definitive choice as to who you think red john is!
