(((((Merrygoround)))))
WELCOME to SR, happy to see you here, but sorry for the reasons that brought you to us. There is great Experience, Strength and Hope (ES&H) on this site and it is free for the taking.
You asked, so here goes. lol
As to your son. Since you have a "No Contact" order in place, although I am not as sure of Canadian laws as I am of those in the U.S., I do believe you can go to court and get "Supervised Visitation."
This will solve a good part of your dilemena in that it will be an impartial observer at each visitation (to protect your son), it will show your son as he gets older that you did not try and prevent his father from visiting, but that you were very concerned about your son's welfare, and as time goes on, your son will have 'limited' contact with an active addict.
Somewhere down the road, should the child's father regain his senses and get clean and sober and start living a clean and sober live, changing his ways so to speak, the "Supervised Visitation" order could always be revised or closed by the court.
I admire your courage in protecting YOURSELF and YOUR SON.
As far as him 'paying' child support, please get a court order for that also whether you need the money or not. If you can live without it, great, put it in a fund for your son's future college. This is part of the CONSEQUENCES of HIS ACTIONS that he is RESPONSIBLE FOR. Thus, if he chooses to become a 'deadbeat dad' in addition to his other problems, there will be more CONSEQUENCES through the COURTS for his actions. Doesn't matter that he has 'no visible job' in that I am sure Canadian Courts are similiar to here in the U.S. and the judge doesn't care, will tell the father to get a job, and order X amount to be paid monthly or weekly, etc. When not paid, eventually the courts go after the offender and lock them up. Child support has become a BIG ISSUE in Family Courts both here in the U.S. and Canada. Holding the men responsible for their part in producing a child.
This is called CYA (cover your azz).
We are here for you, there are many on this board that have been where you are. Please keep posting and let us know how YOU and that beautiful child are doing, we do care so very much.
Love and hugs,