[Toddsterpatriot]

However, the BUT part states they must use gold or silver to repay debt.

Article 1 section 10 prohibits states from making any Thing but gold and silver Coin a Tender in Payment of Debts.

The Federal government is not limited in the same way by the Constitution and the states are not "making any thing".

Does the US govt have the gold and silver to back up the paper bucks in circulation?

No.

Especially now, when we all know the fed is printing money out of thin air.

The Fed has always created money out of thin air. That's what central banks do. The only recent change is in magnitude.

[takenoprisoner]

What exactly do you fear regarding a complete audit of the fed?

Be specific.