I've thought from the beginning Misty is the key... I don't think she's afraid of Ron. I think she was "good" to the kids because she knew that was the way to "get to" Ron, thru the love of his children. The myspace message to A, walking out on the interview (even KC didn't have the guts to do that!), the fact that she had to grow up fast and be in survival mode at a young age, the rumors of her cheating on him... I think she is uneducated but extremely street smart and a master at manipulation in "her" world and men in particular. I think she has Ron and the Nieves buffaloed, and possibly some of LE... I don't think Ron had any part of this, he's not the brightest crayon in the box and I think she has them all fooled. Hopefully the LE that got her mad can break her.
I think Misty either wasn't there, brought an SO into their "lives" and this set everything in motion (not cousin JO) or it was an accident on her watch.