So, what would you suggest I take as in skills on the tree if I was to be a Shadow-Mage slash Vampire\Necro slash Assassin?
I want to be sneaky, if I want too, I will only use bound weapon spells for melee and wear cloth armor. I would raise the dead to aid in my cause.
But also I want to charm, as a vampire can do. But if I was surrounded but many enemies, I would need to reach deep within myself and bring out chaos.

If you made a character with this description.
Then.. what 3 skill tree would you start with?
And what total of skill tree's would you take?
And which perks would you really need to make this character "complete".

One thing that is very helpful for vampires is the level 70 restoration perk necromage.
I would say its the difference between a powerful creature of the night and a so-so vampire.

Is it unatural for a vampire to use spells like frost or fire or lightning?

Not at all, vampires are normally mages, or at least in skyrim they are.

despite popular culture these days vampires have a very core idea. Vampires are weak, they have alot of downsides such as but not restricted to:

-cant enter building without permision
-cant go out in the sun
-deathly alergic to holy water, garlic, etc.
-distinct visual cue's that one is a vampire
-etc.

two major skill trees i recomend are
-illusion
-sneak

shouts i recomend are
-throw voice
-detect life

Vampires are well known for their ability to seduce and instill terror into people/victems, and very rarely simply charge head long at an opponent. example:

Barbarian A attacks a fort with bandits in it, he runs through the front gate attracting the notice of everyone and soon comes under attack, he dispatches some that close on him with his greatsword, and soon chases down archers that had shot at him from the wall. once the outside is clear, he makes his way down into the fort. . .

now

Vampire A sneaks close to a fort of bandits in the dead of night, improved night vision coupled with detect life tells him exactly how many, and were, all the bandits are located. the bandit guarding the entrance hears something in the darkness off to his side, and moves away from the door (throw voice) The vampire creeps into the shadows of the fort. once again the bandit hears a noise, and is joined by a fellow bandit who claims to have heard it too, and they nervously begin to search the darkness for its source. the Vampire has a choice now he can simply leave them be and sneak into the fort, or create some chaos. he instills insanity into one of the bandits minds who begins to wildy attack his friends. snickering at the sound of bandits fighting each other the vampire descends into the fort.


both methods get the job done, and melee maybe faster, but i feel the vampires aproach requires a little more finesse and is its own reward

Why sneak? Illusion will cover that with the Muffle and Invisibility?

because invisibility wears off if you step on a leaf, muffle is nice though.

sneak also gives you:
-dont set of preasure plates
-sneaky role
-bonus sneak attack damage
-etc.

i see illusion magic such as muffle and invis as tools to augment your already good abilities, not as cure all's

Each to his (or her) own, I guess. I already have a sneaky Khajiit dual wielding assassin, so when I rolled up a Dunmer nightblade with plans on becomming a vampire someday, I purposefully did not perk the left hand of the sneak tree, preferring to rely instead on invisibility and muffle. But, yeah, I did perk the right side up to the bow perk, for the enhanced damage. With fortify one handed gear, the 6x sword damage is comparable to the 15x dagger strikes, so I saved a perk there and leave the daggers to the Khajiit.

Re: the OP. If you want to be sneaky while using bound weapons you will need to pick up the quiet casting perk in the Illusion tree. My Dunmer nightblade only used bound weapons until he got high enough level to find ebony swords. Those look so good in his hands that he cannot resist using them. He still only uses bound bows, though, no regular bows.

Here is the build I am using (up to level 51) for the Dunmer nightblade I am using, who sounds very similar to what you are proposing.

Archery 8
Overdraw (5)
Eagle Eye
Steady Hand (1)
Power Shot

One Handed 5
Armsman (5)

Alchemy 8
Alchemist (5)
Physician
Benefactor
Poisoner

Illusion 9
Novice
Hypnotic Gaze, Aspect of Terror, Rage, Master of the Mind
Animage, Kindred Mage, Quiet Casting
Dual Casting

Conjuration 7
Novice, Mystic Binding, Soul Stealer, Oblivion Binding
Necromancy, Dark Souls and Twin Souls

Restoration 5
Novice, Regeneration, Necromage
Respite
Apprentice

Enchanting 8
Enchanter (5)
Insightful Enchanter
Corpus Enchanter
Extra Effect

the suggestions i gave were of one of my characters

Alexia Vulf: Level 81 nord vampire.

levels split between magica and stamina, not allowed to pump health.

perks
left side assassin tree
full illusion tree
left side conjuration tree
left side restoration tree (necromage)

Rules: Not allowed to actually kill anything, something else has to kill people.
no armor (light, heavy, or alteration)
no magic resist or absorb
no weapons (1 handed, 2 handed, shield, bow, etc.)

assassin tree is actually cool because the final skill that makes people loose sight of you does not break invisibility if you cast it on yourself, i have run from a mob before and cast muffle, then invisibility, then crouch into sneak and they cannot find me despite the fact that im in front of them in daylight.

i rely on casting frenzy like spells from stealth, and then reanimating the dead or summoning a dremora lord to finish things off.

relies fully on stealth and not being detected, very easy to be 1 hit killed, and relies on confusion and letting people or creatures kill each other whilst safely in the shadows, summons come in handy when there is only one monster or i cant control em.

I wouldn't bother taking any Apprentice>Adept>Expert>Master mage perks, just go novice to open your way to other perks.

In Restoration, Regeneration>Necromage is a must have. I usually take Respite too.

Illusion: Take every leveled effect perk, up to Aspect of Terror, also quiet casting is awesome if you want to play with people without being noticed.

Sneak: Don't bother taking more than the first Stealth perk(vampire sneak bonuses are awesome and will suffice, also I'm sure you'll be using some other sneaking items) but take everything else.

Conjuration: I don't take the bound weapons related perks anymore, theres plenty of items you'll be using, also being sneaky you'll have the time to develop strategy for every occasion, including cast soul trap on enemies you intend to trap.

Alchemy: Awesome, full perked if you want, I usually take everything but the higher ones, Snakeblood and purity aren't(on a vampire) worth it imho.

Light armor is interesting but wouldn't put in high priority, just remember: if youre going light armor, avoid melee at all...

Other perks are related to your combat strategies, if going nuke destruction or archer, maybe one-handed... going all of them is hard, mostly take one and perk it as you level...

Also a Master Robe for the school of your choice and some magicka bonuses items for those dire moments... Fire abatement items to fight fire dragons... dark brotherhood gloves/boots, etc...