"...there were too many red flags, such as a clause waiving the right to sue if the government failed to honor its side of the deal."
That's not a red flag. That's an absolute show-stopper. A contract that allows one party to choose whether or not to perform its side of the deal, while binding the other party, is legally not a contract.
No federal worker should even consider this, particularly in light of whom that other party is, and his history of not paying people.