Yes. If the court finds out about the settlement before it is disbursed.
In most cases, no. Child support in Wisconsin ends when the child is 18 and has graduated high school.
State child support agencies may intercept tax refunds to collect past-due child support.
The State child support agency can intercept your tax refund, yes.
No.
Contact the MO child support agency for your county.
Only if there are arrears on the child support case and you can convince Child Support Services to garnish the settlement or the bank account of the other parent.
"settlement" ... to collect past-due support, yes.
Yes.
Yes.
Only if the child is being adopted.
Yes, the IRS can intercept your tax refund for back taxes owed; also if you have government student loans that you owe on and also the child support division can intercept you refund for back child support owed.
Generally, child support is based on income, not assets.