needs some icons and images.

Silence is WAYYYYY better than a bit of damage from upgrading your spells.

Seal of Potency is DEFINITELY not a good choice. It gives weak AP and uncomparable to some other rune's efficiency.

WAI NO UP REVOLVA? Lol, but since you got it this far, Wota won't hurt too much.

Your regen is weak. Good hands > Perseverence almost forever.

Many of the situations won't happen too easily. In fact, most of them won't happen (The carry won't rush all the way to take your tank out. Not unless he doesn't know what a tank is.)

Supports are important targets, second to carries themselves. A good support will leave your entire team boosted and have second lives, but it is not THAT drastic to rush and take the support out. More often than not, its a bait.

Hey dude I like the spell vamp idea.
you would get LOADS of of health back from a single cast. HOWEVER:

You absolutely need one point in "Call of the Void" to give you all the dmg output poss.
Having another level in a spell will never outweigh having a new spell to dmg with.