He can't sue for back squat. He was ordered to pay it so he has to pay it. They cannot go back and change the past.
He is lying and trying to scare your mom out of getting what is owed to her. Tell her to goto court and request he hand over his tax returns so you know exactly what he has made. He has to pay weather he is working or not.
If he works under the table, find where he is working and take pictures to show he is lying about having a income. Don't back down!
His new spouse is not your parent. She has no obligation to support you and your siblings.In the US one can pursue many remedies, wage garnishment being the most effective. You can apply for assistance with food stamp and help with electric bills.. If he overpaid, that's his problem.
He can't get it back now. The judge can require his to produce his tax records. Then his proper income can be considered for child support.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.