I have three themes throughout my post: implementation, gear inequality, and energy.
First the proper in game infrastructure does not exist for a few skills, items, and abilities. Into this category falls a lot of cool things that have been implemented, but there is no satisfactory infrastructure to support these ideas. For example, the spear ability is a very cool idea. I like it that three classes share a single weapon type. Warriors have the choice between two damage types: slash and pierce. Rangers already do piercing damage; spear doesn't give them more choices but in actuality narrows the skills they can use. Rogues also do pierce; spear narrows the skills that they can use as well. So the spear ability and items are very cool ideas, but the in game mechanics don't support spear characters yet.
I used spear as a main example under this category. There are other things that fall into this category as well, like skills: (play dead; conceal; smoke bomb; calm; howling wind; certain wards) and items: (old mega-consumables; mage frozen armor; druid frozen armor/totem; mage frozen wand; wolf hats; red boss resistance charms) and abilities: (spear, axe, blunt). All of these ideas are/were very cool, but lack proper implementation. I, myself, am sad when cool ideas are added to the game only to be shot down by the community due to poor implementation. The mega-consumables are a stellar example. Mega-consmables were an awesome idea, and I was sad to see them go(The blizzard scroll was awesome! please bring it back

). The reason they left had nothing to do with the idea, but how they were implemented. The reason the community complained was because they spent an hour killing a boss only to get eight 10 second flame resistance potions. Similarly, all those things listed above are great ideas, but just were not put in the game correctly.
Since this post is about mages, I'm going to zero in specifically on poor ways mage and mage items are implemented. First, sacrifice doesn't have enough in-game mechanics to make it worthwhile. There are not enough situations that need mages to sacrifice other members of the group. There is no way to tell which group members need energy or not. Mages don't have enough skill points to invest in sacrifice. So these problems combine together to make a problem that I think is sufficient to be on my list of poorly implemented skills.
Second, the mage wand is a problem. Mages gain almost all their energy regen from sigils. I am going to get into this point a little later, but I'll provide it here as well.
Cloak at 49 costs 367 energy. cast every 2 min.
Firebolt at 48 costs 347 energy. You cast firebolt every 6 seconds.
Lure at 35 costs 172 energy. cast every minute.
Regen from items in combat is 75 energy every 5 seconds (25 from offhand, 15 from crown, 20 from neck, 10 from braclet, 5 from ring).
Imagine that I cast one firebolt at 367 energy. How much time does it take to make that back? Well at 75 energy in-combat every 5 seconds, It will take 30 seconds to regenerate the energy that I used to cast one firebolt. Imagine I cast 10 firebolts because I'm in a boss battle. It will take a little over one minute to cast 10 firebolts. That means in minute I have spent a total of 3470 energy. After the minute has passed, I have regenerated 900 energy. So I have a net loss of 2570 energy. If I sat out of the battle, it would take 3 more minutes to regenerate that much energy. At this point a mage thinks, "ummmm, yea?" 3 minutes is a lot of time to sit and do nothing. Plus you are going to run out of mana 1 minute after you wait 3 minutes. So in every 4 minute interval a mage is only getting 1 minute of playtime. Also consider the fact that the mage is only casting one spell, firebolt. What if i wanted to cast firebolt and iceshard?
Long story short, mages buy large amounts of sigils to fix this problem. I personally have over 500 sigils. That means I can regenerate 500 energy in a 5 second period if i am out of combat. So instead of 3 minutes of downtime, I only have 10-15seconds (you normally get out of combat regen as you wait for firebolt to cooldown.) Sigils allow me to keep my current damage skills and not have to get sacrifice or e boost.
So because I use sigils, that means I cannot use auto-attack. If i auto-attack with wand, then I lose my out of combat regen. So while it would be very cool to use the frozen wand and get the bane of crom proc, it is not a good idea. Consequently, I don't even carry a frozen wand in my backpack anymore.
This situation leads my into my next theme, gear inequality. Every class has the potential to get the same energy regeneration from their items. The max is 75 in-combat energy regeneration per 5 seconds from items. 75 energy is more than enough for warriors, rangers, rogues, and sort of for druids. But as I showed before, 75 energy is nothing for a mage. So mages are getting the short end of the stick when it comes to luxury items.
Regeneration isn't really one of the biggest problems in gear inequality. The biggest gear inequalities comes from the resistance formula, mitigation of incoming damage due to resistances, and (not a gear inequality but poor implementation) lack of variety in monsters. Physical resistances are closely tied to armor. For every point in armor you get 1 physical resistance. This inequality has been increasing since warden armor was introduced. It got progressively worse when meteoric and frozen arrived. I suspect it will continue when dragon gets here. The problem is that a mage's physical resistances are equal to the physical resistances of a warrior in ancient plate. The physical damage on Stonevale bosses is measured up against a warrior in ancient plate. The damage is scaled to be moderately difficult to a group whose tank is in ancient. Warden, Meteoric, and frozen armor gave tanks huge armor bonuses and thus physical resistances. The frozen warrior physical resistances is nearly 2.5 times greater than mage. This means that physical damage monsters are scaled to still be moderately difficult for a warrior with high physical resistances. But what happens when monsters are still difficult to high physical resistance classes? It makes it much more difficult for low physical resistance classes.
The idea used to be mages were good at taking less magical damage (ex. mage frozen armor has high bonuses to mitigate spell damage). That still is the idea, but it has poor implementation. Mages have(used to have) the highest magical resistances. So they would take the least amount of magical damage. The problem is there are no monsters that mages can fight to take advantage of their magic resistances. All monsters leveling up do physical damage. Occassionally they do skill shots, but very often the skill shots do physical damage as well. So while mages has all these great evasion resistances and magical resistances, they are unable to use them because the proper situations have not been implemented yet to give these numbers any meaning.
I orginally planned to add a paragraph or two about mage damage skills, but decided against it. I think that the some of biggest issues are slow casting times and skill points. Spending skill points in lures is a problem because of a lack of transparency. Since there is no way to find out the resistances of the monsters you are fighting, people just dump points into lure skills and hope it helps. For example, I keep pierce lure at 30. But one time I went to 42 pierce lure. If I didn't pay attention, I would never have realized that for most monsters the pierce resistance hits 0 with 30 pierce lure. So I had essentially tied up 12 points in pierce lure that could have gone somewhere else. So my story should illustrate how difficult it is to "shoot in the dark." You put points in lure to help with damage, but don't know when you should stop.
Also consider the skill point trade off to solve energy issues. Every point you spend in sacrifice and energy boost translates into less points in other skills. So between lure skills, energy skills, and energy shield(mages need this because of the lack of physcial resistances) mages are very tight on skill points. Again I think these ideas are very cool, but they are just poorly implemented in the game.
So I would now like to sum everything up as best I can. The idea that mages can function as a support role is cool. It just has bad implementation. So many things are hidden that it means players have to guess or spend many hours figuring the system out. Mages can give other characters energy, but the way to find out is if someone says so, which is a bad way to do it. Mages can increase the damage of other characters by lowering resistances, but they have no idea what the resistances of the target are. Another issue is caused by gear. The gap between phyical resistances creates a situation where low resistance classes receive extremely high amounts of damage. The regen items benefit low energy cost classes the most, and do very little for high energy cost classes. Finally, a lack of skill credits hurts mages.
1.I think that I have come up with some creative solutions to this. What if there was a advanced user interface that you would turn on from the settings menu. You could then identify the monster the same way you identify player. But the menu would give resistances, health, and energy of the monster. OTM claims that if they released information like this then you lose an element of mystery from the game. But I claim that you all are keep this so hidden that people think your ideas are crap and want refunds because they don't know what is going on. I will cite an example where lack of transparency actually fuels desire to play. WoW had an add on that everyone used that gave you your average dps. Anyways, I think you can make a compromise on this issue. Make the stats of small monsters open to everyone and hide the stats of larger monsters.
2.I think mages need more skill points.
3.I think there need to be mage specific monsters that have high magic damage and low physical damage while mages have high magical resistances.
4.I think it is still way too tough to solo monsters in the otherworld for all classes, especially mages though.
5.Most importantly, I think that the ideas above that are cool but poorly implemented should be given higher priority than they are now. It is cool to add new stuff and invent new things, but there are so many half-way implemented ideas in the game that you could seriously increase the quality of the game by spending a little time fixing them.