Well sure but that's not an argument in favor of libertarianism as an answer to the dangerous working conditions for ship crew either. A government that is focused on property rights, just like the flags of convenience under which most maritime shipping takes place, doesn't care much about labor regulations or immigration in the first place. In a way, international waters are already the "libertarian state".
In some sense, yes. See https://www.econlib.org/archives/2005/07/the_economics_a.htm... and https://www.econlib.org/archives/2017/05/cruise_ships_an.htm...
I was suggesting that if you want to help workers, you need to give them access to better outside options.
Libertarians don’t want non-existent governments as the highest priority. The key priority is using markets to determine prices and a critical part of that is being able to enforce property rights. A big government focused on enforcing those rights is completely supported by libertarians.