Some people say casual shouldn't speak when they haven't even cleared DSR or they have just cleared P8S this week lol.

What is the definition of a casual and what's the definition of who has the right to speak on OF?

Short answer, anyone can talk on OF. I mean, you do.

In all seriousness, only people with proper knowledge with a background check should be talking regarding balance. What I mean is;
- Does the player have cleared ultimates (big bonus) and savage content on time?
- Does the player properly know the role he's talking about? (You'd be surprise how many people comes to OF "claiming" to voice true balance when they only play 1 job since Stormblood and it is of course much more harder to play than anything they haven't played.

Difficulty is subjective but one thing remains the absolute truth. Any job because very easy to play after countless hours on the job in high end difficulty. There's a few people who do manage to clear high end duty and they are legitimately average to mediocre players. They will always log grey no matter what and they can't seem to be able to play their job and their job is "hard". I have a brother who I raided with who couldn't play Warrior optimally. He just never cared enough but also he isn't on OF to say nonsense.

Then you have the other kind of player, the one who makes everything he touch looks so easy and good. They just know exactly how to optimize and play the job well. Great. They'll also say that pretty much any job is brain dead.

Objectively, on the caster role, BLM takes more time to learn than RDM/SMN. Just by looking on casters in term of complexity;
BLM : https://www.thebalanceffxiv.com/jobs...dvanced-guide/
SMN:

RDM: https://www.thebalanceffxiv.com/jobs...dvanced-guide/

You can sum it up by saying BLM has many options to optimize. To the point of stupidity. Summoner is impossible to optimize due to the nature of the job. RDM has some optimization. But I'll be real. I don't need some "advanced" guide to tell me it's best to embolden on a Verflare/Verholy. I sorta figured it out by doing basic mats of 12.7s+7.5s under a 20s buff window. Same for triple melee combo, you want to pot on Scorch. So with both up, Embolden > Verflare > Pot > Scorch is the most optimal gain. Same goes for Contre Sixte and Fleche. If they are up and you're like 5 seconds from buff windows. Unless you know it'll cost an extra Contre Sixte/Fleche at the end, you might want to hold them on rebuff window. But that optimization only works if you do speedruns and nobody is bringing a RDM for speedruns :') Also, I guess people can figure it out but I pot on 2/8 minutes if possible because 0/6 is really bad on RDM. Having 1 melee combo under a pot instead of 3 is a big oof.

You know, there's an amazing system in game on paper but is not so great on reality. It's call the Mentor role. There are a few great mentors and then there's the ones that are mentors for the burger king crown and they brag about it. "I'm Mentor and I say you pull it you tank it. I'm right, you're wrong because I'm Mentor."