I use Manjaro, but I run it like vanilla Arch (for example pacman/yay and not pamac). I find this to be a sweet spot for me - rolling releases are so incredibly nice, and Manjaro being slightly slower than Arch is good from a stability standpoint in my experience.
I use ZFS all over the place, including the root storage pool on my home server, which has overall been a great experience with systemd-boot.
Definitely. As much as a centralized /c namespace is against all the principles of a decentralized system, lack of a centralized namespace results in topical duplication and hinders discovery. I don’t know how, but seems to me some sort of happy medium has to fall out.