Paternity

What are a father's rights if another man signs the birth certificate in Pennsylvania?
I would like to know what are the rights of a father if the mother has another man sign the birth certificate in Pennsylvania. I would like to know my rights if someone else signs the birth certificate. Can I petition for a paternity test?
Can my sister force paternity tests for her daughter?
My sister had a baby. During the time of conception she was sexually involved with one guy and his brother and one additional guy that she married. She named her husband as the father of my niece on her birth certificate and he and the child has bonded as father and daughter. She is now 11 years old. She lives in Alabama and the presumed father lived in Alabama until he recently got into some trouble and was then deported. As my niece has gotten older my sister thinks her daughter looks like the brothers. Could my sister force the brothers to be tested? If paternity is proven who would be legally obligated to support the child her ex-husband who has already been paying support or one of the other guys? Would the other guy have to pay back child support and would he be able to immediately receive partial custody of my niece if DNA testing proved he or his brother to be father?
Can I change my children's birth certificates without high legal fees?
When my two daughters were born in 2004 and 2008, I was told I had to legally place my 'husband's' name on the birth certificate although we had been separated for years and he IS NOT the natural father. The natural father and I questioned the people doing the birth certificate about this and they informed us that it was legally required to put my ex's name on the certificate because the divorce wasn't final. My ex is willing to relinquish parental rights so I can have their names changed and place the natural father's name on their certificates, however, I have been quoted retainer fees of $2000.00 to do this. Is there an online procedure available without having to pay out this outrageous amount?
Can a biological father claim rights if paternity is disproven?
The man who has established paternity is not my son's biological father and he wants partial custody, once I prove that he is not his biological father. Can his biological father claim his rights?
How can I secure visitation rights after a split?
My girlfriend and I had a child out of wedlock. The baby has my last name on the birth certificate and I pay child support. How do I insure my visitation rights in the event of a split?