Prestige Class

Hey guys I am working on this prestige class with my DM for his
campaign. It is a possible alternative to the Mage of the Arcane order
from the Complete Arcane. Tell me what you guys think and if it is
Balanced. Thanks in advance.
Through out the land of Thundain there are naturally occurring and man
made arcane vortexes known as Taps. These are the conduits which
emanate magic into the world. With out these taps spellweaving would be
impossible and mortal magic would die. Some of weavers however have
learned to break the laws of traditional spell weaving and access the
Taps power directly. These weavers are known as Seekers.

Seeker
Hit Die: d4

Requirements
To become a Seeker a character must meet the following criteria.
Knowledge (Arcana): 8 ranks. Knowledge (Geography): 4 ranks.
Spellcraft: 6 ranks.
Spells: The ability to prepare(Arcane preparation feat if spontaneous
caster) and cast arcane spells from all schools of magic. Ability to
cast Arcane Mark.

Class Skills
The Seeker class skills (and the key abilities for each skill)
are Alchemy (Int.), Concentration (Con), Craft, Decipher Script,
Gather Information (Cha), Knowledge(Int.), Speak Language, Profession
(Wis.), Spellcraft (Int.), Use Magic
Device (Cha). See Chapter 4: Skills in the Player's Handbook for skill
descriptions.

Skill Points 4 + int. modifier.

L BA F/R/W Special Spells Per Day

1 0 0 0 2 Spell Tap,Fimiliar +1 level of existing class
2 1 0 0 3 +1 level of existing class
3 1 1 1 3 +1 level of existing class
4 2 1 1 4 Spell Tap +1 level of existing class
5 2 1 1 4 Flash Void +1 level of existing class
6 3 2 2 5 Spell Tap + +1 level of existing class
7 3 2 2 5 +1 level of existing class
8 4 2 2 6 +1 level of existing class
9 4 3 3 6 Spell Tap +1 level of existing class
10 5 3 3 7 Void +1 level of existing class

Class Features
All the following are class features of the Seeker prestige
class.

Weapons and Armor: Seekers gain no additional proficiency in any
weapon or armor.

Fimiliar: A Seeker's class levels stack with previous class(s) when
determining fimiliar abilities.

Spell per Day: When a new Seeker level is gained, the character
gains new spells per day as if he had also gained a level in a
spellcasting class he belonged to before adding the prestige class.
She does not, however, gain any other benefits a character of that
class would have gained (improved chance of controlling or rebuking
undead, meta-magic or item creation feats, hit points beyond these he
receives from the prestige class, and so on), except for an increased
effective level of spell casting. If a character had more than one
spellcasting class before becoming a Seeker, she must decide to
which class she adds each level of Seeker for purposes of
determining spells per day.

Spell Tap (Sp): Beginning at first level and again at 4th, 6th, and
9th,
the Seeker may choose a new spell tap. A Seeker may memorize
that tap as one of his spells for the day and may then cast any spell
on his spell list,
from a school associated with that tap of the appropriate level. Any
Meta-Magic feats must be applied when first preparing the spell (i.e.
3 lvl slot holding an extended 2nd level tap). The mage may prepare
total spell levels equal to his total arcane caster level in this
manner. Casting a spell from a spell tap is a full round action.

Example:
Clou Wren a 6th lvl Sorceror, 4th lvl Seeker, has prepared the Deltan
Soul Springs in a 4th and 3rd lvl slot, and The Rikian Fire Gate in a
3rd lvl slot. This would give him access to 1 4th lvl Enchantment or
Conjuration Spell, 1 3rd lvl Enchantment or Conjuration Spell, and 1
3rd lvl Evocation or Transmutation spell.

Flash Void (Su): At 5th lvl a Seeker can sense the incoming energies
from marked taps. Thus 1/day as an immediate action with a successful
spellcraft to identify the spell being cast, a Seeker may burn a
prepared tap with an associated school of equal or higher lvl to
counterspell that spell.

Void (Su): At 10th lvl a Seeker may disconnect himself and a 20' radius
around him from a tap he has access to. This effect acts as an
antimagic field against that tap and all schools of magic associated
with it. He may use this ability once per day for each tap he can
access for up to 1min.

Known Spell Taps
Eo (Enchantment, Conjuration)
Indrastan Temple (Divination, Enchantment)
Numarian Burial Pits (Conjuration, Necromancy)
Triaddus Wastes (Evocation, Transmutation)
Academy of Corillia (Abjuration, Evocation)
Breolis Ruins (Necromancy, Illusion)
Oasis of Bastion (Transmutation, Divination)
Cliffs of Mythria (Illusion, Abjuration)