So what do you suggest?
Do away with AoE attacks entirely and just base the entire fight around an enrage timer, forcing you to perfect your job rotation and nothing else?

Skill is in executing your rotation at the same time as managing fight mechanics. That's why we have both mechanics and an enrage, which is perfectly comfortable in normal mode.

All mechanics were new at some point. So what if he hadn't played the Ivalice Raids? When you play the Ivalice Raids, you're encountering that mechanic for the first time anyway.

I played Ruby normal four times yesterday, each time clearing it with different friends for their first time, and with 4-6 other newbies each time too. Each time, the liquifaction and comets caused us a wipe, and each time we got it the second try. So what's the problem?
Can you really not bear to wipe even once?