Dead thrall is an excellent spell - as I learned from my first character.
However, after a long skyrim break I'm making a new char and want to maximize its usefulness this time around.

(TL:DR version at the bottom!)

I learned the following: Using necromage from restoration will make all spells 25% more effective for undead. If I become a vampire - Necromage counts your own buffs and spells (Read this on skyrim wiki), so this means you can raise level 50 creatures, up from 40. I also read that thralls will always wear the armor they die in. This means pickpocketing your enemy and giving them a full set of daedric armor with fully enchanted gear - would make them wear it, and keep them when ressed?

So basicly I need:

Enchanting.
Conjuration.
Restoration.
-Train pickpocket and sneak up some, or trade sneak for Illusion.

The plan is to roleplay a vampire and use 2 x Vampire thralls.

Normally one would have to settle for the lvl31 vampire masters as the next tier is lvl42. But thanks to necromage we can ressurect the lvl42 master vampires. Whats bugging me is that with necromage you can reanimate up to level 50. However the juiciest price of all would be to enslave Volkihar master vampires which are level 53. Which brings me to the following question. Is there another trick to make you able to get those last 3 levels?

A vampire's weakness is fire. My plan is to create 2 full daedric sets with fire resist, magic resist and whatever more and plant them on the intended target before killing them and reanimating them.

Ultimate price? 2 x Volkihar master vampires at my side in fully enchanted Daedric armor, these also have reanimate spells of their own and that should be rather amusing in a large combat.

----
So!

1) Necromage allows you (as a vampire) to reanimate lvl50 mobs. Is there a legit way to push it to lvl53?
2) Is it a MUST to plant the gear you want your thralls to use - on them - before they die?
3) Will cheaper spell cost enchants work on thralls to allow them infinite spellcasting, or do thralls as followers have infinite mana by default?
4) Any other tips and tricks for dead thralls?

Thanks in advance for any help

necromage does not work on master volkihars but there is another way get a master vampire go to the docks in windhelm commit a crime and you will have a volkihar master vampire
2 you cannot equip a thrall with armor but you can enchant their armor simply take it off and put it back on then go through ankther cell you can however give them shields and weapons i suggest you enchant weapons with absorb health so they do not die
3 fortify schools do not give thralls stronger damage or less spell casting cost
4 also master volkihars in my experience svck because you cannot give them weapons or upgrade their armor
also you cannot have two or more of the same thrall ex: two master vampires they will die when entering a new cell
I recommend these thralls
melee bandit cheifs and forsworn ravangers
archery forsworn ravangers
magic slid the warlock volkihar vampires and master mages

NPCs will not equip armor other than what they normally wear unless they are a follower, but I believe that they might wear their old armor if enchanted, as mentioned above.

Vampires are skilled in light armor, so Daedric is a pooor choice; however, sometimes Volikhar appear wearing Glass armor.