Yes. Android 10.0 Operating System supports multiple users on a single Android device by separating user accounts and application data. For instance, parents may allow their children to use the family tablet. Here is a link to instructions for doing this: https://support.google.com/nexus/answer/2865483?hl=en

That will depend on the requirements and compatibility of the specific game you want to play. This Lenovo IdeaPad 3 15 Laptop, model number 81WR000FUS, ships with Windows 10 S-Mode 64-bit Operating System. Windows 10 S-Mode provides added security by only allowing APPs available ( and therefore certified by Microsoft) at the Microsoft Store. If you don't need the added security or you need to install APPs not available at the Microsoft Store, you can switch to standard Windows 10 Home 64-bit Operating System, at no additional cost. We recommend you check with the specific game's software publisher's web site for their compatibility with Windows 10 S-Mode 64-bit operating system and the minimum/recommended hardware requirements (Is a Graphics card required, the processor speed and the minimum required system RAM and the minimum available hard drive space) to run their program, then compare those requirements to this system's configuration. If you choose to switch out of S-Mode for Windows 10 Home, here is a link to instructions for switching from Windows 10 S-Mode to Windows 10 Home: https://support.microsoft.com/en-us/help/4456067/windows-10-switch-out-of-s-mode

There is no included tray for an additional hard drive. This would be sold separately.

The Lenovo IdeaPad 3 15 Laptop, model number 82H8018SUS, does not have a fingerprint reader.