Hi honey - i practice family law.
if you name your ex on the birth certificate you will automatically give him parental responsibility, which gives him the right to be consulted on all the big decisions like religion, education, medical treatment etc. it will also mean that if he decides to turn up at nursery in the middle of the day and take your little one the nursery will not be able to stop him.
if however you dont put him on the certificate he can always apply to the court for a Parental Responsibility Order (which he is likely to get) and he can ask for a declaration of parentage so he can get the birth re registered with his name on the certificate.
my advice would be to register him as the dad - thereby giving him PR. he will get it anyway so why put yourself through unecessary stress of the court application.
i would personally only put your surname and if Joseph wants to change it later in life you can do it for him before he is 18 or he can do it himself after. i have seen lots of mothers who have given their children double barrell or the dads surnames only to regret it when they disappear out of the child's life. the child is then stuck with a surname that means nothing to them as you wont be able to change it without your ex's consent.
re the booze - it certainly sounds like he has a problem - he may not need to start drinking as soon as he gets up every morning but if he cant stop himself drinking at some point every day he needs to get some help. i am suprised he is using the term alcoholic tho. in my experience alcoholics are very reluctant to admit thats what they are until they have hit rock bottom and have no other choice.
if he keeps drinking i would refuse unsupervised contact and insist on you or soemone you trust being there. i definately wouldnt allow overnight stays until he can show he can stay sober whilst the baby is with him.
talk to your solicitor about getting a Residence order, this will prevent him removing the baby from your care/nursery without your consent.
sorry for the sermon!!!!