...well first of all, CLEAN is a must.  first and foremost, and ALWAYS required for rimming:  absolute cleanliness.  If you aren't clean enough then no go either way, shaved or natural.

I strongly prefer natural, and not recently trimmed either.  That same chaffing issue you mentioned in your OP is an issue when rimming as well.  I've seen some porn videos where the girl just kind of sticks out her tongue and licks a guy's asshole timidly and without much enthusiasm... but let's be clear:  good rimming involves shoving your tongue deep into someone's ass and showing a little enthusiasm about it (hence the cleanliness is SERIOUSly non-negotiable).  when I get enthusiastic enough with someone's shaved ass, it's kind of like getting enthusiastic with someone's shaved FACE- if they've shaved recently but not within the last couple hours, then that results in some major rugburn.  I'm not into my entire face getting scratched up during sex, so shaved asses and faces with five o clock shadow both result in lower levels of enthusiasm from me during service.

give me natural and I will go wild.  pubic hair is meant to reduce chaffing and allow for friction that doesn't damage.  shaved asses are like porcupines to me... not good at all.

and anyone with a halfway skilled tongue can work their way around a little genital hair.  people who claim that they can't give head properly when there's hair "in the way" are either lazy, unskilled, too used to shaved genitals to learn new strategies, or simply have a bias against body hair and refuse to try properly.  or perhaps simply uninterested.  when you're uninterested in learning how to do something, of course you can't do it properly.

for example, I eat a lot of hairy pussy and I've literally never gotten a hair stuck in my teeth.  so I always laugh at guys who claim it's inevitable.  someone's not very good at eating pussy if thats the case...  your tongue goes between the places where hair grows... hair doesn't actually grow on the clit, inside the vagina, or on the asshole itself no matter what!!  part the hairy sea with your tongue people... and keep it parted!!  it's a skill.