There is no video input mechanical switch within this lenovo Legion Y25-25 Monitor, model number 66AAGAC6US. You will select the video input to this monitor within the Onscreen Menu. Here is a link to the User Guide for the Legion Y25-25 Monitor that illustrates the selections available within the OSD Menus: https://download.lenovo.com/consumer/monitor/y25_25_ug_en.pdf

You can use an external USB-based Windows compatible CD/DVD drive with this Lenovo IdeaPad 3 15 Laptop, like this one: https://www.bestbuy.com/site/lg-8x-external-usb-double-layer-dvdrw-cd-rw-drive-black/5852919.p?skuId=5852919

Yes. This Lenovo Legion Slim 7 15 model number 82K80081US, ships with , the Lenovo Legion
AI Engine, a system of AI solutions, that dynamically shifts power between the CPU and GPU for more FPS on today’s top AAA titles. It can be controlled through the Lenovo Legion Vantage Dashboard software installed on this Legion Slim 7.

The Lenovo IdeaPad 3 15 Laptop, model number 82H801DQUS, ships with Windows 11 S-Mode 64-bit Operating System factory installed. The Lenovo IdeaPad 3 15 Laptop, model number 82H8018SUS, ships with Windows 10 S-Mode 64-bit Operating System factory installed and ships with the Firmware TPM 2.0 Security Chip that is required for upgrading to Windows 11. Here is a link to more information about upgrading to Windows 11: https://docs.microsoft.com/en-us/windows/whats-new/windows-11-requirements. Windows 10/11 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 10/11 Home 64-bit Operating System, at no additional cost.