Only content.info is actually used by the program. Any others are ignored and for use (renamed) as you guessed.
If a person downloads maps (or anything else) from a Sygic Server within the program (as opposed to a stand alone map downloader as can be found here) any existing content.info file will be overwritten and may break the program from full operation.
Footprint.info is created by the program to store valid settings and other information. It is dynamic..start without it, and it will be created. Delete it and it will be created again.
Without a version file that matches both the APK and the base files (just a text file with the correct number code in it), the program will not run, it will try to connect to download one, and it will fail.