Second, I have read the magic topics and I wish this doesn't turn into a flame war or whatever, most comments on them come from ppl that haven't "seen the world" through the eyes of characters using other skills or they would have realized from long ago terms as "one shots" or OP are already into the game with other skill combos. This is not a MP game, OP is not as important as "perceived difficulty" over the lifetime of a given character.
Third, I have played to L40+ a Thief/Assassin and a Warrior (Playing in parallel all the characters) each of them focused on its own way to play and storyline.
Fourth, I always play in Master difficulty.
So my Mage is my third character and I already have a few anoying issues to bring to attention (Not expecting Devs to even read this, but to the soon-to-flourish mod Community) when possible I will provide a comparison with other types of gameplay:
- Skill/Level Scaling. Conjuration Weapons scale, Summoned mobs scale but Destruction, Illusion, Alteration and Restoration does not.
* Illusion provides level-restricted effects as enchanted weapons do, with the advantage to give the Mage flexibility on which effect to apply without having to carry multiple bows to deal with effect/level combos. Works k but durations are fixed.
* Alteration provides fixed defenses akin to the basic armor levels. The problem is that seems that Devs forgot that most are additive with basic armor so going around with robes AND the double armor perk doesn't do anything for any gameplay chosen. This perk needs to provide offensive bonuses when the Mage is wearing robes (Flat bonus to damage and/or magicka regen). Exactly the same differences that there are between Light Armor and Heavy Armor, that trade off defensive perks for offensive ones (stamina regen principally). This disparity is amplyfied to the roof when the character has smithing and wears any armor (You don't even need to invest any perk on smithing, just basic upgrade at 100 skill, something very easy to achieve).
* Restoration healing effects are more or less k due to the slow scaling of HP bars of the player and NPCs.
* Destruction fails to work as a direct source of DPS. The reasson is simple, it has "basic levels" as weapons do (The different spells along the same damage descriptor) but lacks the basic skill scaling ALL WEAPONS have (Conjured ones included). The other, OFC, is that there aren't gear-based damage increasing bonuses at all for magic. This seems to be the "hot topic" on most threads, if you feel the urgency to try to deny this, please, first play as an Assassin and particularly as a 2H weapon warrior (I advise you to stop using a 2 hand weapon at the very moment you start one-shoting everything you have in front... Without stealth. Makes the game trivial. Switch back to 1h + shield or you will get bored in no time). Dual casting on the other schools works because they add secondary effects to the spells... Not for destruction, sadly, it's basically 2 casts with stagger chance (The damage output is EXACTLY that of 2 spells and the mana cost is also double) that requires the Mage to forfeit the flexibility of having 2 different spells active. On Magicka limited scenarios, this perk is simply not worth it, specially if you practice (and have perked) with your wards as a mana regaining system. If you do a simple comparisson with a bow fully perked, destruction is a straight waste. A mage using a conjured bow with less perks (invested into archery instead of destruction) will be a far deadlier (And far more efficient) ranged combatant (Specially if he gets bow damage boosting gear).
- Mana Freeze. This "detail" is behind most of the problems with Magicka regen. The issue is that while casting a spell the mana regen is suspended, simple but devastating on the long run. Doesn't matter the school you use, you spend time aiming, or waiting for the "right moment" or you have to spam the same spell forever to kill someone. During all those operations Mana Regen is simply 0, this makes the mana costs of spells FAAAAAR higher than expected (Yes, even with 100% cost reduction you are spending mana... That mana you aren't regenerating). In particular this renders all Staves innoperative at the very moment the user has access to the spell the particular staff is imbued with as casting spells from a staff ALSO "freezes" mana.
Proposed Changes to bring Mage gameplay inline with others:
- Spell effect Scaling with skill. Duration, damage, protected ammounts and healed ammounts should see a skill based scaling. Spells are "Mage Gear" as basic weapons/armor "materials" are for Thieves or Warriors, makes no sense the later ALSO have Skill Scaling (Sometimes even with 2 skills affecting output) and the former not. Gear effect scaling SHOULDN'T be included, as Physical fighers DO NOT have stamina cost gear reductions. This scaling should carryover to spells on Staves also, ofc.
- Mana should regen at all times (keep the different in-combat and ooc regen figures so mana pool matters also). The only exception to this is when a ward is been kept up, then and ONLY then, mana regen should be 0. In this way the cost of spells will be the real one and staves will be helpfull as an effective way to "save mana" by scrifying souls.
- Enforce the "robe gameplay" by adding "robe only" perks on each school (or a generical "effect booster" on alteration school, the skill tree with less perks). ATM simply doesn't cut it and do not follow the decissions to take as physical fighter regarding the armor you wear. You are naked but gain nothing but "mage-like" looks

- Dual Casting for Destruction should yield higher damage than 2 consecutive casts (+25% should be enough). Impact perk should be changed. It should trigger a stagger ONLY 50% of the time and then should boost the secondary effect of the Damage Descriptor: Electricity - 50% extra mana loss, Fire - 25% extra damage received while burnt, Ice - 25% extra stamina loss & 25% slower movement.
I think this set of changes will make the Mage gameplay consistent at all levels, not the actual "weird" mix with abrupt changes on difficulty, perks that make spells obsolete and schools that are redundant.