Here's a real question...does the writer remember all of these horrors brought upon the family from his own personal memory, or is he depending upon others to tell him what happened? Did his mom convince all of the children of these horrors, or did they really happen?

Changed names, moved to another coast? Why was that necessary after the birth father gave up his parental rights?

This could indeed be a case of a horrible father. It could also be a classic case of PAS (Parental Alienation Syndrome).

I have personally seen a case remarkably similar to this that turned out to be a complete falsehood. The real shame is that the daughter that had this perpetrated against her then repeated the pattern, almost like from a text book. One lie led to another and she invented an entire story with dozens of contradictions. A lie that grew and grew and the only ones hurt by this are the children and the falsely accused father.