I wrote some stuff I thought about him no long ago, but another proof that he is actually the good guy is in the 13th Halloween Special episode of Pretty Little Liars when he tells Miranda:
'Don't try to understand. Not now Miranda.' he puts his hand on her shoulder. 'Just know, you'll be safe. That's what your parents wanted. And, please, forgive me.'
And on the first episode of Ravenswood he tries to get Miranda to leave the place so that might be because he doesn't want her to die. He also tells Caleb to make Miranda's mind up, so she will leave. So all this time he was trying to protect her.
Later on, I think that 'HE' that is mentioned at the end of the last episode of Ravenswood is also Raymond and that he is part of this things ... Also he tries to protect the children and keeps the ghost victims alive ( by keeping pieces of them).
However, I think that Luke's and Olivia's mother knew about what was happening and that their father never liked Raymond from high school and that he thought that Rochelle and Raymond were having an affair and that he tried to investigate and instead of that met Abby and later argued with Rochelle about Abby (the information that we know about her and the night he died) so Raymond got to kill him (Rochelle's husband was stabbed and there is a knife carefully kept in Collin's work place)