If i am owed child support payments mandated by the court which i have not received can i apply that to my tax statement as a loss?

No.  Child support payments, either received or given, are not reported on a tax return.  You cannot claim a loss for income that cannot be reported on a tax return.

No, you cannot do that.  You can petition the agency that enforces child support orders in your area to order that the deadbeat parent's tax refunds be seized for child support owed.  The trouble with that is often they structure their tax withholdings in such a way that there will be little to no refund for the IRS to grab.