You know, his comments to BIL about how he might do drugs just to show EA/friends how to come off? That's a pretty bizarre statement to make - and makes me think he is ALREADY doing drugs with them. Kind of a veiled admission?
You talk about him eating everything in sight - maybe a drug-induced behavior? (Although, really, pot's the only drug I know of that makes you super-hungry - in which case, he'd probably be a lot nicer to live with!)