Yes. The Lenovo IdeaPad S145-15 laptop 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. To install Google Docs, you will need to switch to 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

No. The Active/digital pen is sold separately. Here is a link to an example of a compatible Active Pen: https://www.bestbuy.com/site/wacom-bamboo-ink-smart-stylus-black/5731102.p?skuId=5731102

You can use a USB-based wired mouse with this device. This system ships with Windows 10 S-Mode. 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. Windows 10 operating system has Miracast capability. Here is a link to more information: https://www.makeuseof.com/tag/project-windows-miracast/

That really depends on the requirements and compatibility of the games you play. 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 (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.) 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. Please keep in mind, the Lenovo IdeaPad S145-15 laptop is an entry level, light use system with its Intel Pentium processor. It is not meant for multi-tasking or demanding programs. It is good for Microsoft Office and light internet browsing. If this describes your computing needs, the IdeaPad S145-15 would be a good choice.