Can you actually use examples of your ideas here? There was CC/kiting/more in-depth Off tank adds back in Coil, they really weren't as noteworthy as you might thing. Most of the old raids in WoW similarly did such things. It usually amounts to some players gaining a new assigned role that really isn't as fun as you might hope.
Tanking and Healing need significant reworks if they want to adjust the damage dealing meta. Throughputs are too high and active mitigation comes mostly through cooldowns that aren't reliant upon stances.
So, you WANT very LARGE swathes of content tied behind difficult fights? I thought many people were not wanting this, complaining that Coil was story locked or that extra versions of fights were Savage only?
Spoilers: Any fight in any MMO ever that had 'room for players of all skills' are pretty bad. Doing such a difficult task usually requires:
1.) The boss has so much health and there's basically no cap to the amount of players you can bring, so you just bring everyone with a pulse (Ala WoW 40 mans)
2.) "Everyone contributing" includes people who supply the raid. If you want to make this feel more worthwhile, you start adding virtually mandatory and long farming requirements. IE consumables or gear that's so useful or potentially even required that for every X hours of attempts you need Y hours of farming for materials. This was all of Vanilla WoW, it was harsh and required far, far more hours to actually raid. Know what you're asking for here.
"Tanking or healing as little as possible" is called efficiency. The more picky the requirements are on efficiency, the harder a fight is. Is the itemization and loot tables for primals bad? I'd mostly agree. But the way they're handled is pretty above average as far as MMORPG raid bosses goes.
Right, which is why I'm curious as to your suggestions above. FF11 and Vanilla WoW were certainly rewarding in that time and effort were weighed more heavily than raw performance, but this comes at a very significant time-cost for most players, which really isn't a popular trend these days. (See: any complaints of Relic Weapons)
I'm more of an advocate for 3 tiers of difficult for endgame. As of now, we have a hodgepodge of WoW Normal/LFR for our one 'Normal" difficulty. And our Savage difficulty is somewhere bouncing between "Heroic/Mythic". The problem only made worse by the hard limit of 4-6 bosses per patch at most.