He will not be granted legal custody.
See Link BelowChild Custody- Can Fathers Win
the noncustodial parent is usually awarded some type of visitation rights in order to enable a relationship with the father. If the father is unfit however, them this needs to be brought to the attention of the court that the father is engaging in a lifestyle and practices that are harmful to the child. If that is found to be the case and true, then there is the possibility for either supervised visits or total denial of visitation rights until the issue is resolved.
Yes, either parent can take a child if there is no custody agreement set into place yet. The father will need to hire an attorney and fight the mother for custody in court if he thinks she is unfit.
Possibly
She can terminate her parental rights, not yours.
As long as it is for a legitimate reason you should have no problem having your child taken away or being considered unfit to care for a child. You should be ok.
Unless the father has been determined to be an unfit parent and has had his parental rights terminated the court will try to obtain the father's consent. If the father objects the court will hear testimony and make a determination that is in the best interest if the child. In any case, the father's rights must be addressed legally in order for the adoption to be legal.
Grant him supervised visitation. Your interpretation of unfit may be bias, and a fatherless child always does worse than one with an unfit father. see link
It is unlikely that the court would order "shared custody". If the mother is unfit the grandmother can petition to be appointed the legal guardian of the child. However, the father must consent.It is unlikely that the court would order "shared custody". If the mother is unfit the grandmother can petition to be appointed the legal guardian of the child. However, the father must consent.It is unlikely that the court would order "shared custody". If the mother is unfit the grandmother can petition to be appointed the legal guardian of the child. However, the father must consent.It is unlikely that the court would order "shared custody". If the mother is unfit the grandmother can petition to be appointed the legal guardian of the child. However, the father must consent.
Assuming you are an adult, yes you have a chance.
If he has been established as the biological father you can not stop him from petition for visitation. That is his right as a parent. If he somehow is unfit you will have to prove that to the court.
If you live in the US... The father's parents have no rights to custody at all. The father has the right to petition for custody, but he won't be given sole custody unless he can prove the mother unfit. He might, however, be given joint custody.