I think perhaps you need to be clearer as to what a boundary is. It is not a "law", e.g. banning porn or cocaine in the home.
It is expressing what behaviour you will accept. He can behave how he wants; however, you need to spell out what the consequences will be if he does x, y or z.
Then he can decide whether to behave within these boundaries or not.
E.g. you could say if he uses porn in the house then he will need to move out for one month. Be warned, if you set boundaries and fail to follow through with your stated consequences, you are giving him free rein to ignore everything you ask of him.
From what you have said, I think you would be far better cutting your losses now and getting rid of him. Your children will be better for it - I say this as someone who grew up with an alcoholic parent.
He's using the 12 steps to suit himself. One of them is about making a list of who has been hurt by the alcoholic's behaviour and another step is about making amends. Just saying sorry is not making amends. Refusing to engage with you regarding his financial behaviour is like shouting in your face that he's not sorry.
Go and see a counsellor - for you, not for him. You deserve better.