Bear with me here, this might be quite long and I'm not entirely sure how coherent it will be yet. I am going to try to outline what I think 4dimensions should be heading towards, that should not require huge change like we sometimes talk about, but that could basically be done with three fairly significant alterations to three of our existing features and one new feature. People need to remember here, and really think about this the whole way through: none of these changes will make things harder for you. If anything, the goal is to make things easier but more enjoyable, and it would all require reasonable testing to make sure it worked well, otherwise it wouldn't be implemented. You should keep an open mind while reading and decide if you think the idea's would actually make things a little more interesting for you.
Now, the four features I would like to see change are GM, the movement/mana system and the skills/spells system, and a new weapon/elemental proficiencies system.
First of all, if the GM flag was removed so that you didn't ever get to keep all tier 2 skills/spells in the game, and instead kept your last 8 remorts tier 1-4 skills/spells. This would open new dynamics for different styles of play, Thief/Warrior, Hunter/Priest, Gypsy/Esper - this is actually how it was on the old code, except you kept your last 4 remorts, except without tiers that meant 4 classes. This would probably actually make players stronger, because they would now be able to keep 2 tier 4's at a time if they liked. However, if they thought 1 tier 4 class was enough, they could go Thief tier 4, Warrior tier 2, Hunter tier 2, and now they would be a mixture of 3 classes, but still with one solid tier 4 behind them.
Secondly, if the movement/mana system was altered to be more similar to a type of 'action points' system that most big games use. We already use stamina instead of movement for a lot of things, and it's actually a much better stat. It discourages spamming because it effectively 'heats up' very fast, but it also 'cools down' very fast too. It is kind of like action points, limiting the amount of things you can do in x amount of time. This is different to movement which is just a large total, which only limits the total amount of things you can do over a very large time, but is essentially so out of scale it is a pool by which to sip through straws on.
Also, all movement really does in 4d is stop newbies from being able to explore and run around. Their 'pool' of movement is only a puddle, and it runs out fast and takes a long time to restore. Unlike stamina which is fairly similar for every player, only newbies are affected by this small 'pool'. Now, imagine if we had a similar, stamina version of mana, and lost mana too. Now we would have two sets of 'action points' that were basically 'Stamina' and 'Mana', we would have discouraged spamming both skills and spells by making them both very 'heat sensitive' features basically.
If someone wants to cast a spell in battle, they have to realize it might eat up a significant amount of their Mana, and they need to choose which spells to cast, and choose them wisely. On top of that, if you could determine roughly how much Stamina or Mana to use, ie, by charging your spell, or putting effort into your kick, you could actually potentially do more or less damage with a selected skill in battle. All this would be balanced so even if you only used 2 skills in a fight, you would still kill a mob at the same speed (hopefully even faster) in this system as you would currently. This would hopefully mean that instead of typing behead;behead;behead;behead;behead;behead 15 times in one fight, you only need to behead a mob once, or heart squeeze a mob once, or demonshreak a mob once, or encircle a mob once, (and so you should) and the fight would be largely over. Your stamina or mana would restore quickly, maybe 10 seconds of not using any skills or spells or speedwalking.
The third change would be to the skills system, to try and make some basic skill-trees. e.g. every class actually has a 'style' and roughly two tree's of skills inside it. If you only had enough practice sessions to learn one of the trees inside a class, or half of both trees, then you could really add even more variety to the classes, as well as beefing up each individual tree, because if you can only learn 'behead' but can't learn 'brace' then you can make behead do much more damage and brace block much more damage. This would work very well with the 'remember 8 remorts' thing spoken about above. If you want to do Thief twice, and remember 8 remorts of Thief, you would be able to learn BOTH of the skill trees every class has. And be a truely specialized class.
I will now give a brief idea of how the skill trees might look:
Imagine that the core skills of each class are as follows,
Mage: heart squeeze, inferno, meteor shower (offensive individual, offensive area)
Hunter: behead, bladedance
Thief: backstab, focus, blackjack
Gypsy: slit, phase, sleep
Ranger: encircle, dodge, hamstring
Esper: phase, slowness, corrupt armor (evasive, debuffs)
Warrior: brace, parry
Priest: sanctuary, bless, armor, heal (buffs, heals)
You can almost see they range from very OFFENSIVE at the top to very DEFENSIVE at the bottom.
Mage being either an offensive towards an individual type class, by using a key spell like heart squeeze, or being an offensive towards an area type class, by using inferno and meteor shower.
Hunters can only behead once per fight, but bladedance makes that behead seriously strong. That shit will kill most of the time.
Thieves get backstab a massive opener, and focus to increase the power of backstab, as well as blackjack which can make backstab a one-hit-kill.
Slit would deal ongoing damage, phase would let you avoid more hits and increase the frequency of yours. Sleep puts them under, even in battle so a Gypsy could slit and sleep as a potential to do some damage - though it wouldn't be the fastest.
Encircle for Rangers would be like a less powerful backstab, used in battle. Dodge would make Rangers super hard to hit, and hamstring would cripple the opponent.
Warriors would get brace, maybe reducing up to 60% of the incoming damage, as well as parry, blocking a huge amount of blows.
Priests would get lots of buff type spells, like sanctuary, bless and armor, to make them absorb heavy damage feeling almost nothing. They could also learn heals, letting them heal up during fights.
All other skills would just be prereqs to these main skills, or a lot of them in a pool that all classes can learn, like mount, riding, firearms, etc. I imagine cleave would be a pre-requisite for behead, that warriors could learn too. Sneak would be something many classes could learn, but it would be especially good for increasing the damage of backstab.
Fourthly, and finally: weapon and elemental proficiencies, separate to the skill trees are these proficiencies in every type of weapon: shortsword, axe, warhammer, etc, as well as all of our elemental types, fire, water, air, etc. These are not things you need to worry about learning with practice sessions, these are things you get better at through use. They are zero-sum equations, eg, any gains in one thing result in losses in other things. If you spend all your time using fire, you will not be able to get very good at air, or water. Similarly, if you use longswords most, your other weapon masteries will face depletion. These would all be on scales of 1-100.
This is all I can think of for now.. Have a read, have a think, have a post.