If you need help... :P

The wording on that UESP article is poorly done.  That's demonstrating the effect of a +100% Regenerate Magicka effect in combination with the ring and the player's existing base magicka regeneration.  Without any enchantments or other effects, the player's regeneration rate out of combat is simply 3+2=5%.  That means with a single +100% effect like the Apprentice Stone with no robes or other boosts, you'd be looking at only 10% per second.  You would need +300% Regenerate Magicka to hit 20% per second.

Oh and also, the same flat +2 applies to the in-combat magicka regeneration, meaning 0.99+2=2.99% per second.  If you have +100% Regenerate Magicka from the Apprentice Stone, that's 5.98% per second in combat.

Molag Bal rapes Hircine this character is the offspring....

To me it seems like a wash either way.  The bigger question on my mind is "Dawnguard vs. Volkihar" which ends up being a "power gaming vs. role playing" question.  The quest itself is very wizard friendly with elder scroll prophesies and uncovering the lost artifacts of Auriel.  But your character may have reservations about joining the vampires.  I ran into this with my pyromancer character.  In the end I opted to stay true to the character and join the Dawnguard foregoing the powerful Ring of the Erudite.

Dont forget the Sun Spells. Their taper dmg in conjunction with the necromage perk cuts through the undead like they're made of butter.

It all depends on role play for me. An evil powering mage? Vampire. Or not. I'd never go with werewolf though because of the companions unless I used a sword or axe though.

Does Necromage have the same effect on taper damage duration for the sun spells?  And do Fortify Restoration potions boost the damage the same way Fortify Destruction does for fireballs?  If so, that's pretty effective.

Yes and no. Let me explain using firebolt vs sunfire.
(• Sunfire cost much less to cast, making it overall much more effective than firebolt.)
• Firebolt does 25 dmg instantly and 10% of this dmg over 1 second (this is the taper dmg, which necromage applies to). Other fire spells have more taper duration, but are?'t alway more effective in terms of cost/dmg.
• Sunfire does 25 dmg over 2 seconds (this is the taper dmg, which necromage applies to).

As you see, the whole spell is considered taper dmg (same with it's stronger version), making it significantly stronger than fire-taper effects.

Something that few people know is that this also applies to all destruction rune spells as they do their dmg over 2 seconds (necromage augments the base dmg by 25% and this duration by 50%), increasing their dmg against the undead significantly.

As far as I know, restoration potions act the same way how destruction potions work. Stendarr's Aura doesn't work like the other sun spells.

Necromage is a big gamechanger against the undead / if you're a vampire and with Shadow Warrior arguably the best perk in the game.

Shield Charge is right up there with them! But Necromage is specifically the ultimate undead hunter mage perk. :D