...and the general welfare of the country's workers is ensured by prohibiting slave labor and by requiring employers to provide safe working conditions for their workers. Workers are free to improve their value and negotiate their pay with any employer. If that agreement is reached without coercion or duress, the worker has nothing to complain about.
There is nothing about protectionism that promotes the general welfare of the country; quite the opposite, in fact.
"Establishing justice" - does the word justice means anything to you?
It does. Apparently, it means something different to you. It's interesting to note that "justice" means "give me what I want" to many people. There are very few convicted criminals, for example, who feel justice was served by their conviction and imprisonment.
When employment is negotiated between two parties, the employer and the employee, if both are in agreement to the terms, then the arrangement is just. Each party is free to terminate the relationship if the terms are no longer appealing. If the employee is offered employment for a higher wage, he is free to leave and accept that offer. If a worker offers to do the same job for a lower wage, the employer is free to hire that worker rather than the first. The process is very fair and just.
So according to you, the treason, drug trade, usury, slave trade (in ancient Rome you could become slave because of debt), prostitution is just if based on contract.