These two feats are a little more complex and I’m still not sure about the second one's power and balance. The first was inspired by Monte Cook’s unified magic system of Arcane Unearthed (or Arcana Evolved); the second is another attempt to simulate something I read in novels. Actually – about Casting Focus – I originally wanted to tie it to the Arcane Bond (object) class feature of the Wizard but, after some thought, I believe that that wouldn’t be fair to the other spellcasting classes. Maybe I can come up with something more specific to the Arcane Bond feature (I have my house rules for it, time to recheck them I guess).
You are able to compartmentalize your mind through physical objects, enabling the preparation of more spells.
Prerequisite: Heightened Spell
Benefit: You can use one slot to prepare multiple spells. The only limitation is that the total of prepared spell levels must be equal or lesser to the chosen slot level. For example: if you choose a 4th level slot, you can use it to prepare two 2nd level spells or one 3rd level spell and one 1st level spell. Each of these spells must be tied to a unique focus. These foci are tiny non-magical objects, like a ring, a coin or even just a twig. Each focus is added to the components of that specific spell (even if you have the Eschew Materials feat).
You can only have one spell slot divided each time.
Special: If your DM allows, even spontaneous casters can use this feat, but they must prepare all spells derived from a divided slot like a non-spontaneous caster.
You can use a special mystical object to cast your spells in a more simple and potent way.
Prerequisite: Any two metamagic feats, non-spontaneous caster.
Benefit: Choose one common non-magical object, like a staff or a ring, to be the temporary recipient of a spell. That object becomes your casting focus, an additional spell component. After preparing the spell, the casting focus begins to irradiate a faint magic aura (of the same school of the prepared spell).
If your casting focus is broken (link) or destroyed before you can cast the chosen dweomer you suffer 1d6 points of nonlethal damage per spell level. If your casting focus is stolen, it can be used by an enemy spellcaster against you. Any spell cast by him against you, while holding the stolen focus, imposes upon you a –2 penalty on saving throws and caster level checks (to counterspell).
The stolen casting focus can be undone by its creator the next time he stops prepare his daily spells.
A spell prepared through a casting focus gains the benefits of one or two metamagic feats possessed by the caster without increasing the spell slot. There are only two limitations. First, these metamagic feats can’t increase a spell level by higher the +2. Second, the caster can have only one spell stored in a casting focus. Following these rules a caster could prepare a silenced, stilled spell through a casting focus; or even a heightened spell (as if using a slot 2 levels higher).