You can read your contract or hire an attorney to do it for you. Actions afterward depend on an analysis of the contract.

Other than the price you paid for your pizza, which I suspect was zero, you have no damages. Unless you’re able to prove that they knew you were...

Perhaps consider a complaint with BAR.

By hiring a competent family law attorney who does custody work.

If you properly transferred it to him then you should be okay.

No . . . . . . . . . . . . . . . . . . . . . .

What would you do if someone else was inappropriately given your food at a restaurant?

It would be a personal injury attorney. But frankly you don’t really describe much in the way of “damages” over which to sue.

Depends on whether it was binding arbitration.

Yes. Execute through your family law attorney