This is especially so because the "children's rights lobby" insist that they should be given the same rights as a father who was previously married to the mother of their child and has always been safe/good to their child etc. To my mind this ends up with all decent parents being given equally few rights because of the justifiable view taken by the authorities about the risks posed by the irresponsible ones.
Therefore I can be much harder than most others on this forum when it comes to excluding dads who are as irresponsible as this man you describe. I have no qualms about the courts deciding he shouldn't see his child on the basis of the details you've given us.
One of the greatest irony's of all this attention given to the courts to what they consider the child's welfare, (with all it's professional advisors) is that they contemplate giving irresponsible fathers contact with their children whilst at the same time supporting mothers who are alienating their children from perfectly safe dads.
I can imagine it is a very difficult to be in, and I can fully understand both your fears and frustration. Others here have bought into a whole way of thinking that doesn't fit very well with cases like yours in my view.
I'm sorry I can't be more helpful to you.
All the best, Graham