Hi there, welcome to the forum.
The xdg-desktop-portal crash should be this bug in the Arch reporting system (referencing also the upstream KDE bug, I think).
I noticed that as well in my system, but I must say it is not currently affecting the usability of any application, so I haven't investigated much.
As regards the ACPI errors, well..., you can keep on searching, maybe update the BIOS, searching in the jungle of kernel boot parameters, maybe using this guide (not limited to!), but I think that they are often due to non-standard BIOS implementations.
I think this article summerizes the point quite well: