YA-HEY!
It's not the spell-list that makes the Shaman class. It certainly is a factor, but, let's face it, if it couldn't wear armor, a measly +2 AC for a first level spell isn't giong to markedly increase survivability.
If you take away some of the Monk and Cleric abilities, and lower the BAB to something like a wizard's, then you do have to throw a bit into the mix to keep the class in line with the rest of 'em.
It's doable. For instance, maybe instead of being able to wear armor, they'd cast arcane spells, but be able to...oh, I dunno, spend 1 spell level and get a +4 to an ability score for, like, a round or something? The whole "I'm a weaver of Magic, of COURSE I'm more than I seem" idea...Or maybe giving them some extra damage with a similar cost? Maybe something like the rogue's Sneak Attack done from Magiking up a weapon or something?
It's definately doable. And going with a Shaman as a baseline allows you to only tweak what you'd want to tweak...
Okay, let's take a look at the Shaman's class powers, and see what it might be equivalent to:
Slightly-Midling HP: Maybe a keeper. I'd advocate keeping it. You may be able to give them wizard HP and give them something else that ensures their survival...like a bonus Toughness feat for being exposed to arcane energies, or maybe Shield proficiency so they can up their AC a bit.
Average Skill Points: This would probably be a keeper for a more esoteric wizard...more Knowledge skills of obscure lore, more Craft skills of strange artistry, etc.
BAB: I'd keep it. If you weaken it, I'd say give 'em a HD up by 2 categories, maybe LOTS more weapons and armor, maybe surge their saves with some extra Oomph (probably making them all good). Because these changes probably wouldn't fit the goal, I'd keep it. If the magic is lower, anyway, the physical training is going to be better.
One Good Save: Probably a keeper. We may want to beef it up a bit, and adding another save is a good counter-measure to, say, getting rid of the Unarmed Strike and Bonus Feats, or ditching both the spontaneous casting and the Domain Spells (that might even be worth all 2, but probably not). We'd probably add it in Fortitude, I think...Exposure to the Arcane and all that.
Weapons & Armor: Seems pretty OK for an esoteric wizard. One might want to ditch the whole light armor thing...then I'd suggest upping their HD to a d8, or maybe giving them some sort of Monklike Intelligence bonus to their AC or something.
Domain Spells: Maybe a keeper, representing the forces the wizard knows about. If you get rid of it, it weakens 'em only a smidgen. Maybe give 'em another spell per day, or perhaps some automatic spells as they level up (assuming they don't learn all the spells on their list automatically like most divine spellcasters).
Spontaneous Casting: Probably ditching it. I could see a case for keeping it ("I was going to cast this spell of mist, but it's not very helpful to help my friend or smite that evil"), but it would most likely go. Again, best solved with a spell-learning mechanism, like more spells per day, or giving the spell list a few "must-haves" from the Wizard/Sorc list to beef it up a tad.
Unarmed Strike & Bonus Feats: Basically a bonus feat. May be traded for Scribe Scroll...maybe look at some of the feats in the PsiHB for ideas of what could be more-or-less "latent" magical powers that they don't have to cast, but get anyway (maybe their bones turn to mithril or something, giving them +4 AC. But only as long as they've got 1 spell level, or something). Definately want to trade this out for something that helps their battle prowess, though. Maybe extra weapon proficiencies? Armor proficiencies? Something sneak-attacky (in which case all the feats go)....maybe limiting the feats to a different type, like Metamagic and/or Item Creation.
Animal Companion: Probably a no-go. Since animal companions are actually fairly decent, I'd consider giving them a fairly decent something to compensate. Perhaps a bit more attack spell or defense spell capability, maybe some extra feats, maybe some extra weapons or something sneak-attacky. I can see something more powerful than the Monk Wis-To-AC bonus being used here.
Spirit Sight: Eh. It's only a so-so ability, and I could concieve of it being left in for wizards "attuned to the supernatural world."
Turn/Rebuke Undead, Extra Turning: Again, so-so....useful, but only occasionally. Might want to change it to some sort of innate read/detect magic ability...that'd be pretty handy for a spellcaster.
Spirit's Favor: Probably a no-go. The Wis-to-AC ability is about equal (with a change to Intelligence or Charisma most likely), but I could see it, under different flavor...After all, exposing yourself to evil energies is going to toughen you up a bit, and the better able you are to bind the dangerous forces of unseen to your will, the better you can take a hit.
So that's the idea.
Erm, I personally would probably just turn spellcasting classes into PrC's and have them use the Adept, but I wouldn't be apologetic for having pansy PC's, because then I'd make, say, the Fighter have to be a Warrior for a few levels...Paladins and Rangers may require both Adept and Warrior levels. Rogues may need Adept and Expert...so I'd weaken all classes across the board and use a few "intro levels" before you got to the true power of, say, a Fighter.
...oh, and LV1 would probably be Commonner all around.
But that's just my brainstorm idea plan thing.
