at times yes but usually if the noncustodial parent does want to see the child they will be denied visitation rights and not be allowed to see the child
Not as long as it doesn't interfere with the access rights.
Only the court has the power to deny visitation rights.
see link
Yes, you can adopt your stepchildren even if the noncustodial parent has not paid child support or visited them for a significant period. However, you will typically need to demonstrate that the noncustodial parent's rights can be terminated, which often requires proof of abandonment or failure to support. The process may vary by jurisdiction, so consulting with a family law attorney can help clarify the specific requirements and procedures in your area.
married or single?
It really depends on how the parental rights are divided and should be specified in your divorce/support paperwork.
See raleted queation
Courts usually only allows parent to give up parental rights if the child is being adopted. But if they would allow her, it would be for the custodial parent to decide whether they would need child support or not. If they need support from the state the state will go after the mother first.
Unless visitation rights for the non-custodial parent were allowed in the divorce paperwork, the custodial parent is completely within their rights to deny the non-custodial parent visitation....however, the non-custodial parent may sue for visitation rights.
the custodial parent is the parent the child lives with the non custodial parent is the parent the child does NOT live with the non custodial parent assuming he / she knows he is a parent... is usually the patitioning parent. if he /she chooses not to seek visitation rights the court cannot force him/ her to see the child.... but they can enforce child support. research the laws for your state.
How does the two interfere with each other?
With court approval and provided welfare is not involved. see links