thanks for asking.

The only difference between registered version and demo is that you can only use the demo version for 30 days. There are no feature limitations, differences or any different code paths. The exact same routines are in use regardless of whether you have purchased a license and use it - or whether you're still in trial time.

For custom devices like the PS3 remote, you'll generally have to turn on your Mac and boot it fully before you can use it. You can't use such devices if your Mac is still turned off or not fully booted, because the Bluetooth stack that, on the Mac, is spread across user and kernel space will not be fully initialized and working until that point. There may be basic support for BT keyboards and mice directly in the EFI firmware (to f.ex. support selecting a custom boot drive), but the EFI firmware's Bluetooth support should not be confused with OS X' Bluetooth stack.

Like any other OS X application, Remote Buddy needs the OS to have booted fully before it can run and have any influence on what your system does. Prior to booting and launching Remote Buddy, it has no influence on your system - which includes adding support for the PS3 remote.

Best regards, 
Felix Schwarz