LOL

Ok, ok, explain how, in what universe, the magic system is possibly improved? You have less spells that cost more magicka than ever to cast and no spellcrafting at all, so go ahead and explain that, if you would

I haven't got really far into the game and I am not a pure mage, but I find myself breaking out the destruction spells when I need to deal with a mob attacking me.
Many a times have I laid waste to 3 guys at once blasting them with dual fire, it just roasts them and their health dwindles down even after I stop for a few seconds.
Also, there are a couple of things you can do:
First of Enchantments, make a lot of magicka regen enchantments on every apparel you have, I've seen that some Robes and "masks" have 100% magicka regen ALONE.
So then combine that with the Restoration tree's 50% magicka regen and other apparels like gloves etc you can possibly have 200% magicka regen, that is pretty fast.
Then you use Conjuration to have Atronachs do the tanking and alleviating the burden on you, whilst you blast a way with some destruction magic.
Another thing is to plan before the encounter and cast an oakflesh shield to help out if they get close.
Also in destruction if you choose the "use half magicka" perks for the level of spell you use well that along with more than double magicka regen should help a lot.
If you play on a high level of difficulty perhaps that is not properly balanced playing a pure mage, I don't know but then just lower it one level.
Also this game has creatures/enemies that are far higher in level than you in certain areas and you won't be able to handle them until you're a higher level.
I went up against "motherwisp" at low level and it was impossible to even dent her health and she could kill me in 1-3 hits, plus she has wisps that she summons.
Granted now at just level 11 I at times feel over-powered (not mage) using a bow that one hit kills when I am stealthy and also a warhammer that I many times only need 1-2 hits to bash their brains in with for almost instant victory.
Difficulty levels are there for a reason, no one will make fun of you in a SINGLE PLAYER game if you lower it one level from where you have it set at.