Literally every single question you ask about the Finder can be answered by simply clicking on the UI element you are wondering and observing what happens. It would take less than two minutes of poking around to fully understand all the basic controls of the Finder, and during that time, you are very unlikely to damage your file structure. Also, even a moderate familiarity with OS X UI conventions would explain a lot of the functionality.

It seems you're trying to say that any UI without textual labels on everything is not discoverable. That doesn't fit with the usual meaning of the term, and seems to be too strict a standard to be actually useful.