By the way, unless you run your games in windowed mode which not all games support. You will still have to alt+tab to use your second monitor. Also not all games will keep your mouse locked in the game and when you click on the second monitor it will minimize your game.
I have 1440p 144hz Gsync but not IPS. Variable refresh rate is the newest advance in monitor tech and if you are going high end you should definately invest. I slightly regret not spending more and getting an IPS panel.
You can back it all up. Backup your Appdata folder for alot of stuff. Also, I wouldn't rely on it, but when you do a reinstall of windows it will move your old installation and files to a folder called windows.old in the root directory.
Lenovo's have a little button "Secure key" or something. Hit that to power on your laptop and it will give you a boot menu. You can choose to enter the BIOS from there.
You can also use this button to restore your windows 8 partition if you need to, if you didn't wipe the recovery partition when trying to install 10.