Q: Is there any way that characters with no job skills can make a living from exploring rather than monster fighting with the Perimeter Guard?

A: Yes! I will add a special unit of the Perimeter Guard called "Surveyors" that is under the loose supervision of PG Captain Apple - they are less military, and are the type of explorers who can travel fast, light, and tough. They scout the Abandoned City and bring back corrected maps of the various areas to keep the Government and Perimeter Guard informed on the state of things in the Abandoned City.