Будет ли artix работать с обычным инитом(не openrc)?
Будет, если найти все нужные скрипты. Я вот, например, на десктопе использую sinit и он тоже отлично работает.
What is a "legacy" init?
А чем runit не устраивает ?
https://wiki.archlinux.org/index.php/Init
sysvinit and openrc was in archlinux before systemd. they are now "legacy" init. sysvinit is still developed, but we support it not.
theoretically yes, practically probably not. it's not just about exchanging sysvinit for another init, it's about starting services, you need to have a service written for all those packages too. sysvinit used initscripts, but they are hopelessly outdated, the last initscripts on AUR is from 2014.
you can try it :D, but much better and easier is just choosing a distribution with your legacy init instead... ;)