I would like a combination of all ideas ever suggested, implied or thought of regarding the challenge of the game and its focus (or lack thereof) on grouping implemented.
So I envision it like this:
Make a random lottery system where every 10 minutes, 1 type of mob yields ridiculously insane exp (Like 1500-2000 per kill) solo only. Any other type of mob yields 4-5 exp/kill unless you're in a full 8 man party fighting mobs of the appropriate level, in which case they will yield random amounts between 50 and 500.
Also, I would like to give every mob in the game 1 TP move that has the potential under the right circumstances to 1 shot a player or in the case of Marmots, they will wipe an entire party. For instance, every time players receive a cure, the mob will have a 1 in 5 chance of unleashing an instant death move.
In light of the chance for all cures to trigger instant death, the MP cost of cures will be reduced to 1 MP, with a recast of 1 minute. This will encourage players with low health to remove themselves from the fray long enough to be topped off, and reduce the chance of overzealous mages disrupting the flow of combat.
All enemies should also be in a 10 minute rage timer, as per FFXI. After 10 minutes, every enemy will receive -10% damage reduction, +10% STR VIT DEX MND INT PIE, and increasing the chance of 1 shotting players with a sideways glance.
Introduction of Sideways Glance: An ability all enemies gain randomly that allows them to instantly KO any player, pet, automaton, primal, avatar, or any other silly thing they can summon that has hate.
ARC will have their standard ranged attacks replaced with Blood Arrow, which increases damage by 10% at the expense of draining 10% of their max HP. This effect is not removable, no matter how many QQ threads appear about it.
The new job, Generic Tamer, will be introduced. It will summon a.. something, we'll have the random seed generator pick out a name for whatever it calls forth every time. Think FFVI's Shadow, and his dog would do random attacks. It will be similar to that, but much less useful.
Also, a forum minigame will be introduced with path 1.21. Every time a QQ thread appears, its contents will instantly be transferred to an in-game NPC that is notorious for complaining about everything, via Google Chrome.
More bonuses and penalties will be introduced to the party system in future updates. In the meanwhile, players are encouraged to solo mobs 25+ higher than themselves for moderate exp gains. Players caught advancing levels rapidly while in a group will be investigated and possibly be warned or banned for abusing the system.
See, we want to avoid having a FFXI clone, or a WoW clone, but we really want the game to be more like FFXI, or WoW, so I thought I would put more random junk in our random junk.