Hello, About the Fn to use Function keys, you need to check if your BIOS has the setup mentioned in a previous topic here from forum:
Hotkeys without pressing FN? - Laptops / AeroBook - CHUWI | Official Forum
Check the image posted in this topic. If you have this same option in BIOS, it should work to change Function keys main feature.
If not, then it’s up to bios update and I-m not sure how to do it.
About the backlit, mine always turn on when touched even after restarting laptop. Not sure how or why, didnt do any setup.