In many jurisdictions he'd be considered the legal father whether his name is on the birth certificate or not, just by virtue of you still being married to him. But even if you weren't separated you could still give the baby any surname you wish. He can always go to court to contest this, but if you're divorcing and he's not seeking custody he'd be unlikely to prevail in that.

Yes. He IS the father of the child and his name should be on the birth certificate.

It might be important for getting future child support.

You are STILL MARRIED. Legally it is HIS CHILD AS WELL.

WHERE and are you LEGALLY SEPARATED? There is no "answer" without this specific info.

You will want to put him on the birth certificate for child support purposes, but you do not have to give the child his last name.

yes you do otherwise you will find it hard to claim child support..

Are you LEGALLY separated? That means that you filed papers in the court to notify your county that you are married but living separately. If you aren't and you two just decided to split up, then I think he could take you to court for not having his name on the birth certificate. If he is the biological father, he has every right to be listed on the birth certificate unless you have something legally against him (restraining order etc). You can't just not have him listed. You're going to run into a TON of legal problems. I would suggest talking to a family lawyer in your state. They'll be able to tell you the best course of action.

You can give the baby any name you want. The father has no special right to give the child his surname, or to choose the name at all. From a practical standpoint, the kid should have the same last name of his primary caregiver, and the courts tend to agree. You should give him whatever name you will have after your divorce.

Ask the authorities in the country in which you live!