you could have stopped after 1 and 2.
not one thing you listed about this person sounded healthy or like someone you'd want around kids. i think what you might be "missing" is this guy is BAD NEWS top to bottom.
you say he "functions" - if you mean eats, sleeps, breathes and takes drugs, then yeah i guess that is a form of functioning. he can't hold a job, he takes drugs and drinks every day, zones out on tv and sleeps a lot.
to be blunt, let this one go.