T,
Okay no, you are not crazy. YES from what you describe it is NOT normal behavior. It IS behavior of someone who has issues with divorce, or feeling like he was abandoned, adopted or absent parent.
IT's not a fault - if we could figure out the what or why of our kids we'd be able to help them more than we do. Mental and emotional disorders are frustrating, tiring, they wear a marriage to the nub and you both are going to have HAVE to be on the same page with his treatment and discipline plan. HE isn't going to be on the same page and THAT is the fun of raising a child like this.
You need to re-read Smallworlds post and follow what she has suggested you do. Your son needs to be seen by someone, and he needs to be in therapy. He's hurting more than you'll ever know and more than he may ever admit. Just from the little you've told (Mom not wanting him and telling him so)- IMAGINE what that must have been like for him and at such a young age WHAT SKILLS did he know in order to cope?" HE did the best he could and the behavior you are seeing is some of the result.
Did she drink or do drugs when pregnant with him? Has anyone ever diagnosed (diagnosis) him for emotional or mental disorders? Do mental disorders run in his fathers or biomother's side of the family -like BiPolar (BP), schizophrenia, anti-social (some of the ones you may have heard of)? Start gathering this information and get him to a psychologist that can do a series of tests on him and observe him. Some times our kids are put into psychiatric hospitals for a medications evaluation or tweak to get the dosage correct so they can come back home and try to get therapy and learn how to cope. You too should consider therapy for yourself if you are the caregiver. 180 hours a week is a little extreme when you have 2 boys at home with a step=mother.
Some of the things you've said here are red flags for emotional disturbances. Which one? That's going to be up to your psychiatrist and even then - read and educate yourself as much as possible. This isnt' going to go away ever. It will and can become less severe as he gets therapy or possibly medication or placed outside the home for periods of time. Depending on his age - from what I lived through - I would say he has maladjusted coping skills and possibly PTSD (post traumatic stress disorder) possibly from his biomom/divorce and new Mom. Do you know what if anything she did or was there a lot of yelling between her and your husband? Some kids don't recover from that without intense therapy.
Just fishing really - no solid answers - sorry, gonna need some more information to really help, but it's a beginning that you are here and recognize you all need help. Yes you ALL because YOU are going to need to go to therapy also to learn how to help yourself help him - and probably not a bad idea for brother to go also - it's hard being the sibling of a difficult child.
Hugs
Welcome
Star