@datiswous
regarding Ubuntu, a lot of arch Aur package's use Ubuntu deb packages. And some linux stuff is similar, no matter what linux distro you use.
e.g. I had a problem with my wife's Asus eeepc 1001pxd that uses a alc269vb sound driver
I wasn't able to find any solution on either Manjaro or the Arch forums, but did find a solution on a Ubuntu forum after 3 days search.
The problem was somehow a conf thingie between Alsa and Pulseaudio with that driver. So without the Ubuntu forum I wouldn't have found a solution. 
Now the sound is working on her Asus with Manjaro32 xfce on it.
Also dennikali is asking for an Manjaro/Arch solution as far as i have understood, and not a Ubuntu solution, just linking to something from a ubuntu forum, asking if the same is possible in Manjaro/arch.
@dennikali
regarding Fn keys, I don't know which Asus netbook you have.
but if you have a eee pc, there is an AUR package called acpi-eeepc-generic
however it is not possible to install via pamac, or something else as it depends on xorg-server-utils,
which has been removed from repo, which might explain the Aur package hasn't been updated since 2017. (original github package not since 2015)
if you have a eee pc, that it supports you can try the following, and build it yourself.
to be able to build it you need the base-devel package
pacman -S base-devel
more info at wiki about makepkg cmd
https://wiki.manjaro.org/index.php?title=Makepkg
to get the source use git clone in terminal.
git clone https://aur.archlinux.org/acpi-eeepc-generic.git
edit the line depends, in the downloaded PKGBUILD file, and remove xorg-server-utils from it.
before: depends=(acpid xorg-server-utils dmidecode)
after: depends=(acpid dmidecode)
xorg-server-utils seems to have become xorg-apps.
I tried to modify xorg-server-utils to xorg-apps in PKGBUILD, it didn't work, why I deleted it from the line...
And before making the package, i installed xorg-apps, just to be sure.
sudo pacman -S xorg-apps
then in terminal:
cd acpi-eeepc-generic
makepkg
this will create: acpi-eeepc-generic-1.0.2-3-any.pkg.tar.xz
to install
sudo pacman -U acpi-eeepc-generic-1.0.2-3-any.pkg.tar.xz
I have tried on my wife's Asus EEE pc 1001pxd, unfortunately there's no conf file on the git page.
and i haven't had time to dig deeper into it at the moment. So if it works as intended I don't know.
regarding GRUB, if you by accident get it ■■■■■■■ again
I used this wiki article to restore the grub with a manjaro live usb, once i messed up the grub.
https://wiki.manjaro.org/index.php/Restore_the_GRUB_Bootloader
list of boot grub problems tutorials
so you hopefully don't have to reinstall Manjaro if grub gets messed up again. 
kind regards
Strarup