Acer Aspire One Cloudbook FN+Brightness doesn't work, mouse freezes sometimes

Hey Guys,
As stated in the title, I am ruing Ubuntu "Xenial Xerus" 16.04 LTS on my Acer Aspire One Cloudbook 11 AO1-131-C58K. However, while I can use FN+Hotkeys to change the volume, the hotkeys for Brightness settings, in my case F1 and F2 do not seem to work with the FN key. I am currently using xbacklight to change brightness via Terminal but I would love to be able to use my FN Hotkeys again.
I appreciate every help I can get.

Oh, I have tried those various combinations of stuff to edit in grub, that people with similar problems tried, and I also tried a lot of other ways, whatever I could find... Nothing seemed to work so far..

Also I am using the touchpad mouse, which seems to freeze out of reason sometimes. It happens after 2 minutes of work or even 2 hours. The only fix for me is to restart the pc. I am unable to reproduce the error for troubleshooting so far.

Thanks for your efforts.