An alternative to abuse might be a somewhat crippling fear of abandonment. His response to Aiden after she confronted him about continuing on the case after Mac's dismissal was something like "If I say we're good, we're good." He's basically saying "what, you don't trust me?" This would also account for his apparent family-obsession: if you can count on anyone not to abandon you, it would be your family.
My pet theory is that someone close to Danny was involved in Tanglewood, like a brother, cousin, or good friend. He then would have become a fringe member, not exactly a member but to betray the gang would be to betray his friend. His mother's death is another form of abandonment.
Thus he would take criticism as a lack of support, and goes off on his own, trying to prove that he was right and gain respect after the fact. It also accounts for trust issues- it's hard to form trusting relationships when you expect the other person to abandon you as soon as trouble starts.