My opinion on Burke, just my opinion, is that Burke was the victim of abuse by someone in his life. I don't think it was his parents, but rather by someone outside of his family.
The notes from Bonita Sauer, a paralegal for one of the attorneys present at the Grand Jury proceedings say this regarding the interview Burke had with Dr. Suzanne Bernard:
"Dr. Bernhard felt there needed to be more follow-up with Burke in the discussion of sexual contact. The only show of emotion by Burke, other than the irritation with the questions about the actual crime, was when Dr. Bernhard began to ask about uncomfortable touching. Burke picked up a board game and put it on his head an action indicating anxiety or discomfort with these types of questions and that there was more that he was not telling her. Dr. Bernhard asked Burke if he had any secrets, and he said, “probably, if I did, I wouldn't tell you, because then it wouldn’t be a secret."
I know many people disregard the notes entirely. However, this does reflect actual statements made in the video of the interview.
Burke being abused could explain much of his behavior, both that which is alleged and that which is seen on the interview tapes. There's the reports of scatolia, the inappropriate responses to his sister's death, and the stories regarding his temper.
This is just my opinion based on the evidence I've seen.