this is the last of the support he owes. we have been paying it but both of us are out of work now so it's not like he's a dead beat dad that hasn't paid in yrs. we have made sure it has been paid.
1. Could they force him to sign this without a lawyer
2. what problem is this for me and my children
1. They can't FORCE him to sign without a lawyer. He certainly can choose to do so.
Of course, hiring an attorney and fighting it might well cost a large fraction of the amount he'd have to pay to clear his name.
2. If he pays off his arrears, it won't have any problem for you and your children.
If he fails to pay off his arrears and if you try to sell the house, then it might interfere. The bank would take their money and you and hubby would have what's left.
If you were to divorce, the situation changes slightly. Worst case is that the amount he owes gets taken off the top and you and hubby would split the different. OTOH, you could easily argue in a divorce case (if such were to happen) that the arrears should come out of your husband's share of the proceeds and your share would be protected.
But, seriously, it's only $4,000. He needs to pay it off. Have him take a second job as a department store Santa for the next couple of months. That would take care of a large portion of the arrears.