And funnily enough, he doesn't even pay any child support anyway! He owes thousands in arrears, and the only money I ever received was from an interception of an inheritance he received and garnishment of his wages for a few short months. How can someone request to pay less than the $0 they currently pay? It's absolutely ridiculous!
Just a suggestion that helped my niece and may or may not help you. Would he be willing to sign off ALL parental rights if you were willing to forgive the child support not paid (and not likely to be paid in the future anyway)?
You are supporting yourself and your child anyway and this would get rid of his reason to contact or annoy you, once and for all.
Just a thought, it may or may not work for both of you, but in my niece's case it allowed her to move on and leave the baggage of her (abusive) ex behind.
No matter what you decide is best for you and your daughter, please get legal advice on his request to pay less and possible solutions.
My heart hurts for you. Your child is blessed for having such a caring mother.