Are you having any problems using your flight simulator software on Windows 8? You said some people said it could cause problems, but do you have any? If you aren't having issues then I would not bother with changing the OS.
It may not be quite as easy to do as BikerEcho has indicated. If your laptop is UEFI based instead of BIOS based (many newer computers that come pre-installed with Windows 8 are UEFI based) then there are extra steps you will need to take to be able to install a new OS. Here's a YouTube video that shows what you need to do in case of a UEFI based computer:
As Biker said, you will lose everything on your boot drive so you will need to reinstall all of your addons. Your data can be backed up and restored but all of your programs will need to be reinstalled.