Dear developers,

for the love of Akatosh, stop it with the "half or double" nerfs and buffs.

Make yourself a chart of pros and cons of abilities. Then assign them a value, considering how much they strengthen or weaken an ability. Do that with one patch, not drawn out across several. It'll probably look like this:

Effect Chart
Note: The numbers are just an example to explain the system.

Damage over Time (DoT), 10 seconds
Evaluation: DoT damage can be cleansed and healed against. In PvP, it avoids apparent one-hits; drawing fights out is a good thing in PvP to a certain degree. DoTs cannot be stacked by the same character. Thus, a boost to damage is a.) necessary to compensate for the lower burst and possibility of avoiding DoT damage and b.) of limited effect on total DPS, as DoTs cannot be stacked. Cost can remain the same or be lowered.
Evaluation: +100% Damage

Area of Effect (AoE), 6 m
Evaluation: Abilties of this kind are supposed to be used against groups of enemies. PvE mobs usually appear in groups of three in solo PvE and three to six in group PvE. Damage can be lowered, as the total damage done to that amount of enemies will still be higher than when using single target abilities. Also, cost should be increased to avoid people spamming AoE on single target enemies, instead having to also skill and slot single target abilities.
Modifiers: -25% Damage, +50% Cost

Area of Effect, static
Evaluation: Static Area of Effect abilities (traps, ground based AoE) can be avoided even easier than other DoTs, including by PvE mobs. This should be compensated by a damage boost and cost reduction, as this may require to recast the ability several times before its duration would have run out (DoTs) or without it hitting (traps).
Modifiers: +25% Damage, -25% Cost

Melee Range
Evaluation: To use melee range abilities, you have to spend more time on movement. Also, standing closer to your enemy makes you more vulnerable to counterattacks, and in boss fights, melee characters will have to move out of danger zones more often. Thus, damage needs to be buffed to compensate for the time lost to movement.
Cost should be the same. The ability will be used less often, assuming the character needs to move more. But as movement also costs stamina, resource costs can remain on an equal level.
Modifiers: +25% Damage

This has to be repeated for added effects such as heals, snares, vulnerability and so on, as well as for skills with direct damage and DoT components. Class skills should be given a bonus; personally, I'd add an effect for free instead of increasing the damage or reducing the cost to make it easier to balance damage output and sustain.

Example Ability stats
Assuming a base damage of 5,000 and base cost of 2,500 for an ability, and additive modifiers we'd get the following stats:

Force Shock
Direct damage, ranged
5,000 damage, 2,500 mana

Concealed Blade (without any bonus effects)
Direct damage, melee
6,250 damage, 2,500 stamina

Wall of Elements
AoE, DoT, Static, Melee
6,250 Damage, 3,125 mana

Volley
AoE, DoT, Static, Ranged
5,000 Damage, 3,125 stamina

Impulse
Direct damage, AoE, melee
5,000 damage, 3,750 mana

Using a system like that, it shouldn't be that hard to achieve a somewhat balanced, rational system, without having to buff or nerf evertyhing into high heavens or oblivion every patch.

Draft something. Post it here for feedback. Then publish the final result. Than implement it in one patch. Until then, please, leave things alone. You're just making it worse currently.