Witches, Covens, and Ritual Magic

One of the things that I really enjoy about the flavor behind the Witch class is the Coven, a group of hags, witches, and warlocks working together, pooling their resources to unleash some powerful effect on an unsuspecting world (even if it is only a darn tasty pot of chicken soup). The coven ability comes from the hag herself and has the following abilities:
Hag Covens

When three hags of any type gather, they can form a coven to gain increased magical ability. Any combination of hags can form a coven, but green hags are the most common members of such foul gatherings.

Whenever all three hags of a particular coven are within 10 feet of one another, all three of them can work together to use any of the following spell-like abilities: animate dead, baleful polymorph (DC 18), blight (DC 17), bestow curse (DC 17), clairaudience/clairvoyance, charm monster (DC 17), commune, control weather, dream, forcecage, mind blank, mirage arcana (DC 18), reincarnate, speak with dead, veil (DC 19), vision.

All three hags must take a full-round action to take part in this form of cooperative magic. All coven spell-like abilities function at CL 9th (or at the highest CL available to the most powerful hag in the coven). The save DCs are Charisma-based, and function as if with a Charisma score of 16 unless one of the hags has a higher Charisma score, in which case the spell-like ability DCs are adjusted by that hag's Charisma modifier.

At the GM's discretion, certain more powerful hag covens might have additional spell-like abilities.
Pretty powerful stuff. The Witch has a coven hex available to her that allows her to be part of this group as well.

Coven (Ex): The witch counts as a hag for the purpose of joining a hag’s coven. The coven must contain at least one hag. In addition, whenever the witch with this hex is within 30 feet of another witch with this hex, she can use the aid another action to grant a +1 bonus to the other witch’s caster level for 1 round. This bonus applies to the witch’s spells and all of her hexes.
With the requirement that one of the coven members be a hag, chances of actually using this feet for that purpose is low. You 'could' take leadership and get a hag cohort, but that leads down a road that few GMs wish to tread. +1 CL is nice, though other hexes so vastly overshadow it and it's so rare to have more than one witch in a group that it's hardly ever taken.

The Hexcrafter magus archtype grants access to this hex as well so in theory a magus and witch could feed off each other. All well and good, but as I said there are better hexes out there to choose from.

The Accursed sorcerer bloodline also gives a similar ability.

So there's all these classes with the ability to be part of a coven, but that coven must always include a hag. Why? And why does a coven have the same abilities? Doesn't really make a whole lot of sense to me. So here's the proposal I've been working on.

Any character who may join a coven may also form one. A coven has certain requirements and provides some benefits to those involved.
* Minimum of three spell-casting participants.
* Forming a coven requires a 10 minute ritual that prepares the participants
* Adding a member to a coven requires a 1 minute ritual to prepare them
* Coven members must remain within 30' of the coven leader. If anyone exceeds this distance they are unable to participate in the coven unless added again.
* Spellcasters select a number of spells prepared or spell slots, up to their own caster level, to donate to the coven. These are lost until the spellcaster regains their spells for the day. These powers are added to a spell pool.
* Donations to the spell pool may be made at any time by any member.
* The spell pool is a collection of the spell levels of the donated spells or spell slots.
* The spell list is a collection of all spells available to spontaneous casters, and all patron spells or domain spells, and any prepared spell donated to the spell pool.
* In order to cast a spell from the spell list, an appropriate amount of spell levels are drawn from the spell pool. The caster must be able to cast a spell of that level.
* Only the leader of a coven may cast from the spell pool.
* When a spell is cast from the spell pool, the caster level of the coven leader is increased by 1 for every other member of the coven.
* Spells cast from the spell pool have their DCs based off the charisma bonus of the caster rather than their normal primary attribute.
* Spells cast from the spell pool have a minimum casting time of one round.

Participating in a coven has it's own benefits and rewards:
* All cantrips and orisons known by all members of the coven are available to all other members. These may be used as though known to the caster.
* All hexes known by all members are available to all other members and may be used normally (must still have the hex class ability)
* All Metamagic and Item creation feats known by all members are available to all other members.
* Spells not donated to the spell pool may still be cast normally, there is no benefit for being in the coven for this.

Ritual magic is another thing available to covens. A ritual spell is a powerful spell, usually more powerful than any one spellcaster can manage on their own. A ritual spell need not be known beforehand, only the desired effects. Only the coven leader may cast the spell, and only if their augmented caster level will permit it. Twice the number of spell levels for the ritual spell are removed from the spell pool, the casting time increased to 10 minutes per spell level, and a spellcraft check (DC 20+2x spell level) is required to successfully cast the spell. Each member in the coven provides a +2 aid another bonus to the coven leader for this check. Other factors may help in this check as well.
* Expensive material components. Every 100gp in material components gives a +1 bonus to the check.
* Blood Ritual. Every 10 hp sacrificed (from the caster, coven members, or some other sacrifice, willing or not) grants a +1 bonus to the check
* Special time. Solstices, New Moon, Full Moon, Eclipse, Lunar Eclipse, cosmic alignment, etc may grant bonuses to both spellcraft checks and caster level
* Special place. Sacred groves, temples, mountain peaks, caves, etc. Certain places may grant bonuses to both spellcraft checks and caster level
* Non-members. A spellcaster who is not a member of the coven may participate, but they may only donate spell levels and a +1 to caster level, no bonus to the spellcraft check.

Participating in a coven shouldn't be limited to those of a particular class or birthright, so there's a feat for that!

Coven[General]: You count as a hag for the purpose of joining a coven. In addition, whenever you are within 30 feet of a hag (or someone who counts as a hag), you can use the aid another action to grant a +1 bonus to the other spellcaster’s caster level for 1 round.

Any comments and suggestions for the above are greatly appreciated.