The Volume Locker function protects against an accidental ringer volume changes by pressing a side keys. Since version 1.9 the application has an option to lock ringer mode. Ringer mode (also known as ringer profile) can be changed by a side volume keys too. So it make sense to protect ringer mode as well as ringer volume.
When Debug Mode is switched on the application writes to the log file basic information about device (model, vendor, Android version) and the current application settings. All changes to the application settings are logged. This make debug log more informative and will help to solve problems easier.