Happy to help. Most questions are answered below; email for anything else.
The shortcut does nothing. On the version from this site, make sure ScreenLock is ticked in System Settings, Privacy & Security, Accessibility, then quit and reopen the app.
I am locked out. Press your shortcut again to unlock. If you turned on emergency unlock in Settings, hold the Escape key for two seconds (or press Command-Option-Escape).
My Mac still slept. Keeping the Mac awake covers idle system sleep. Closing the lid or a scheduled sleep will still sleep the Mac.
Email [email protected]. Expect a reply within a couple of days.