Current classes/jobs are too simple

[kyuven]

"Opportunities" basically means you want optional mechanics. This...kinda already exists. For example, the rocks in Garuda HM are now considered "optional." The pillars in the Fenrir fight are technically optional, as you can survive without them.
Fights are actually scripted to include these, such as, using garuda as an example, using the shield from the spiny plumes to survive garuda's attack. Or hell literally everything about the cerberus fight.Your example is...well, having an ability that places a DPS at the top of the hate list is an absolutely horrendous idea from many different standpoints, as that's basically a Provoke, and is open to a TON of abuse. Developers must be very careful adding these skills, or else you create...
Well, to give an FFXI example...you run the risk of creating something akin to NIN/WAR Blink Tanks.
While that sounds interesting, it makes design a nightmare.
And there already are many bosses with "opportunities" to completely cut loose on DPS. For example, t10's boss does nothing after the adds go down before it throws out its big AOE. During this time, the tanks and healers can switch to their DPS rotations, and the DPS can cut loose since they don't have any mechanics to dodge. It's during this time that a lot of MNKS, NINs, DRGs, etc. use their potions since they can maximize DPS.
There's also cases where some classes are given special options for avoiding mechanics, especially ninjas and black mages. For example, both of them can effectively ignore the Avalanche ability from Shiva by using Manawall or Perfect Dodge. In addition, MNKs, NIN, and DRG have options for dealing with the frozen floor in that fight. Not to mention how many things can be mitigated or avoided with skills like Repelling shot.

A rotation didn't exist, only general knowledge about which decisions were better.

that just means you have more rotations, not getting rid of rotations.
In X situation i use Rotation A, in Y situation I use Rotation B.
To use an example, in EQ1 and many other, older games, resistances and vulnerabilities were a thing. This usually meant you had to use another skill from a massive pile of skills. Rotations still existed, there were just more of them and they lasted a lot longer.
Again, rotations DID exist, they were just adjusted to a particular type of fight rather than a universal one for a given class.
This was an implementation nightmare, and had the consequence of requiring more skills for every class to the point a the 255 spell limit actually had to be raised.
And few of those spells saw much real use.

[Sylkis]

"Opportunities" basically means you want optional mechanics. This...kinda already exists. For example, the rocks in Garuda HM are now considered "optional." The pillars in the Fenrir fight are technically optional, as you can survive without them.

All optional mechanics are from overgeared faceroll battles. Unfortunately, all the current content have hard enrages that leave reduce the options to "Must do" or "Ignore" , rather than running out of resources or soft enrage

or stance dance manual micromanage scholar

I already do this, and its probably the only job that I find somewhat fun.




About the difficulty stuff: it can be a new class/job and not a change to the current ones.