Hi Paula. Sorry but I have to say that you really don't know a fraction of what he's going through. My parents are both addicts, they have been since before I can remember, and one thing you should know about us (the most important I think) is that we are TRAINED to shut up. If we talk to anyone about our family or parents we get in so much trouble. Every time we have to talk to someone, CPS or a phycologist or even an outside family member, we are questioned when we're alone again. Repeatedly.
The one and only time I offered information to someone I was 7 years old. It was to a school nurse. She contacted my Mom and I recieved my first (but by no means my last) lecture on "Family Business Isn't Anyone Elses Buisiness" And then I was spanked and grounded.
If you do get custody of him (and I hope you do), know that he will probably never tell you the whole truth, not becouse he wants to lie, but because it's so ingrained in him that it's second nature, like breathing. And you'll need to work on his confidence. There's an overwhelming loss of control that comes with being the child of an addict. He will also probably try to get that feeling of control back in other ways. That can come as obsessive planning, eating disorder, body modification (peircing, tattoo, hair dye), being a neat freak, or just generally trying to control everyone around him.
These tend to show up when we're a little older, mine showed up around 15. There's a forum here called Adult Childern of Addicted and Alcholic Parents (it won't let me post the link, I tried, sorry) there may be more people there who can offer you insight as to what it was like when we were younger and how best to deal with that.
Lots of love and hope,
Riane