My experience is arch is more stable than ubuntu. Broke once in the last 10 years, because of a bug in a package, fixed the system with manual upgrade from live usb in 1h.
AUR is not part of the archlinux repositories, it’s a community thing with mostly the same security problems every similar package manager has (npm, gems, etc.)
1-1, we did not learn anything except you don’t like arch.
My experience is arch is more stable than ubuntu. Broke once in the last 10 years, because of a bug in a package, fixed the system with manual upgrade from live usb in 1h. AUR is not part of the archlinux repositories, it’s a community thing with mostly the same security problems every similar package manager has (npm, gems, etc.)
1-1, we did not learn anything except you don’t like arch.