In SC, can you agree to waive $6,000 in child support arrears and a promise to let paternal grandmother have visitation for biological father to sign consent and relinguish so stepfather can adopt?

Is the state involved in collection of any of the arrears, is any of the arrears to repay government for benefits

Since you need an attorney for this, he should be able to work it out.

All adoptions requrie an attorney. Which ever one you hire will be the best person to ask because they will know all the details of your case and the local laws. Many times back support is "forgiven" when adoptions take place. However, if you were on assistance and the government still needs paid back they won't let any of that go.