also he states several diagnoses that he has. He lists Aspergers, Tourettes, Manic Depression/bipolar, ADHD as some.
A main reason why I dont think he did this is because he literally shares everything on Facebook. Anything he does wrong. If something happens, he either gets majorly depressed or majorly angry. His posts after she went missing did not seem that way. Im just unsure if he can control his rants enough to keep quiet about a murder. Also, he really has seemingly protected Natalie over time. When she got in a car accident in VA, he drove across country (supposedly at her request) to make sure she was ok. He had several very angry rants towards people who had hurt her.
Obviously by his posts this seems to be him, but after reading many of his posts over the last few days, the behavior doesnt fit the crime IMO.