I found a workaround, I just need some help implementing it:
When restarting the mouse service responsible (psmouse) with my script
sudo rmmod psmouse -f -v
sleep 5
sudo modprobe psmouse -v
the trackpad and -point gets detected again, even when undocking and redocking again, I don’t have a clue why, but after restarting (EDIT: the script, not the PC) I get the right behaviour, until a full reboot, then the fix has to be applied again.
My only problem is, that I can’t add that script to /etc/profiles as it requires root access, and on login the screen just stays blank. Had to boot into my installer usb and revert that change for it to work again.
Regarding the other issues, the extra buttons and onscreen keyboard, I haven’t looked into these in detail yet, as the trackpad was the biggest issue for me, which I wanted to fix first.
Maybe I can make the extra buttons work with a workaround similar to the trackpad fix?
And again a big thanks to you for helping me fix the issue and I’m really enjoying manjaro linux, especially because it makes this laptop run much faster as in Windows.