Lost Android Phone data security

• You haven't mentioned if your device is encrypted ; if it isn't you are in bigger trouble. See this Why encrypt the device?




• 100% security is a pipe dream. Given enough resources, it may well be possible to use means available in public domain or those available to the letter agencies to get information out of your phone . Point is that you need to address the security threat. If you are an average Joe who doesn't have sensitive information to justify using sophisticated techniques, you are relatively safe




• Once your device is erased, so will those apps you mentioned be erased , unless they have been made system apps. Logging into a device with PIN lock is theoretically possible by brute force methods, I believe . Locked bootloader and USB debugging disabled make it harder ; but then back to the threat model. Is the information contained important enough to justify that ?




• As far as hardware methods are concerned some typical ways are covered in one of the answers linked in the first bullet point

I believe that you cannot get a definitive answer but for an average user encryption along with locked bootloader, USB debugging disabled and PIN locked on an erased device shouldn't be a concern - your bases are covered