Again, I feel like the code-for-convenience Dexter would (A) probably move to some third-world country where people go missing more often and the cops rarely notice, (B) join a mercenary militia or spec ops force where killing the 'right people' is totally legal and expected, and/or (C) not target other lethal serial killers who are perfectly capable of killing him back. Dexter as a self-serving sadistic coward is hard to reconcile with observed behaviour.