Step Daughter problems (need advise)

I feel for you. I just went thru a bunch of drama with my step son.
He has been out of high school since 08 and has yet to hold a job. He did join the Army, was gone for awhile and managed to get put out. He just refused to train. The freaking US Army couldn't threaten him to do the right thing!
He sits in his room and plays video games all night and sleeps all day. He socializes with no one, unless they are on the X-box 360. He will talk to people there, but no where else. You have to tell him to bathe, to put his laundry away, to do anything around the house. He won't hit a lick unless he's told to do it, several times. My wife enables him and it's caused a lot of problems between us.
I haven't said anything about it here, but I've been having some heart issues.
I've had a few heart attacks lately. Anyway, two Friday's ago, I had just been released from the hospital, my daughter made a comment to him about shoveling snow and not letting me do it. He got pissed off and took a swing at me. I went nuts and beat the **** out if him. He actually called the cops on me. They basically told him it would be self defense and he'd go to jail for assault. I didn't press charges because I knew my wife would bail him out and pay to defend him.
He's out of the house and I don't want him back. I don't trust him.
My wife actually got mad at me because I defended myself. She said I shouldn't have beat him because I out weigh him by 80lbs. I told her my fat, old, bad heart having *** whipped her son. I wasn't bragging, but didn't like that my wife was defending his actions. Told me she couldn't believe I was going to make her chose between her child or me. The kid has been out of the house and I haven't seen him. My wife won't say much about him to me. I guess she's helping support him still. I do know that his Dad wouldn't let him stay with him.
My wife wouldn't talk to me or sleep with me for 5 days after. I finally told her we were a partnership or we weren't. And if we weren't then it starts right now, she needed to leave. I wasn't living with someone who hated me.
I don't know what the answer really is. My son and step son are just a few months apart, raised the same way since they were 8. They are world apart. My son is enrolled in college, has worked since he was 15. Still driving the same car I gave him when he was 16, and is generally a good kid. So it's not environment, and my son likes to play video games with his friends too. I don't know if we fucked up somewhere, or what the problem is. I do feel your pain, I know what you guys are putting up with, to a point. I guess I'm lucky, he's too lazy to get a girl friend to get pregnant. I'm sure I'd be raising that kid too.
I can't suggest anything anyone else hasn't, I've tried it and it doesn't work. But you know that.
I've decided that I've had enough. I'm to the point that I'm willing to walk away from the whole situation. I'm willing to give up my house and everything in it. I'll just buy a new one. It's worth it at this point.
Good luck my man.