Assume max level, full group/raid geared, BIS augments, max AA, all that jazz. Playing the class to 100% potential, which class is the hardest/most difficult/most stressful/non stop playing/always doing something/etc class to play? Obviously a generalized broad term, but try your best if you want.
I'm probably wrong as I've only ever played monk at a high level (and that was years ago) but if I were to guess, I would say druid, shaman, or enchanter...or monk considering how bad I am at training new monks...
As a day one bard, who felt the pain of class identity, group role ambiguity, re-worked, re-tooled, re-balanced, nerfed, buffed, sidelined and often maligned... I would have to say, still, to this day. To play at 100% peek, the bard is the most complex to master and by far the most fulfilling class in any MMO ever to exist. The journey to perfection was long, but worth the song and dance. BARDS4LIFE You can always just muddle by with auto-twist, but a true bard key binds songs/AA to their 12 button mouse and plays a live DJ mix to pull, mez, split, buff, regen, DOT, melee, haste etc etc etc
Definitely almost possibly the hardest class to play in EverQuest to 100% potential is the one you have least experience with.
As someone who has played all classes to some point, cleric does need a lot attention, coordination, and good reflexes. The difference to other classes is that mistakes are not forgiven and do result in quick deaths.
Druid > Cleric > Shaman Healers in general get a lot of crap because missing heals leads to death, which leads to blame game. Druid is bad because they have to really balance mana, aDPS and keeping group alive Cleric is bad because you are bored silly spamming the MT/OT or end up playing "whack-a-mole" all night doing spot heals. Shaman is bad because you are always casting something, keeping up with aDPS, heals, dots, etc.
Bard is both the easiest and the hardest class to play for these reasons. And it is my fav, also for these reasons and it's just fun to me.
Shaman. They have the most options that "might be" the best thing to do, at any given moment. Flexibility, always able to do something productive. Other than the tank slot, can replace any member of your group and do their job, often better. (and sometimes even the tank slot).
In raids probably tanks. Positioning mobs, keeping an eye on what's going on overall during events, knights may be tasked with kiting something etc. DPS classes ... Before dot consolidation, I would say necros were difficult to play. Back then, you could tell very quickly who was good .
Absolutely Shaman. One of if not the largest toolkit, highest APM and target switching requirements, extreme variability in dps and healing based on split second decision making, potential to OT during raids all while still devoting some level of your focus to being able to heal on reaction. As a top level shaman it is very rare that I complete a raid event and think that I did even within 10% of my potential, maybe 1-2 events a month I feel like I played perfectly.
Druids should not be in any discussion of class difficulty. Druids are the best class for newbies who want to play EQ due to all the conveniences they have...port, gate, sow, heal, buff, DS, summon, DD, DOTs etc etc. Druids are the EQ EZmode class...if you have a grandma who wants to play EQ, are you going to suggest they play a druid or a warrior/enchanter/cleric/bard/necro/etc ? I rest my case
Druids do die to fast for being a good newbie class and they are pretty complex. A good newbie class is non-complex and tanky which would be warrior, paladin, shadow knight, ranger and monk for the first 50 levels. Wizard, shamy (root rot) and bard are also easy. Rogue is only easy inside groups and the zerker is even easier because of a higher snare availability when soloing. Snare and root are definetly big factors for easiness and melee classes are more straightforward which does make them easier to learn. Pure pet classes (NEC, MAG, BST) are more complex which does make them more difficult but the beastlord is the easiest of them because it is also a melee class with a neglectable pet and very limited spells until lvl 50. I do think that the beastlord got invented as a class for kids because it does start pretty simple and because kids do like animals.
Maybe true on a tlp or to like level 60, druids are probably closer to the highest complexity on live. Unless that Druid is a type who uses a shield/1h because it helps their “survivability” and spams the 5 sec cast time group heal, which is may be quite a few of them. Probably sham or dru played to a high level is the hardest .
Mercenary. Only capable of doing what they are told but blamed when anything goes wrong by the cheap a$$es that don't share enough loot to live on.