In the comparison between sorcerers and wizards, sorcerers seem to get the short end of the stick. Short-term versatility through spontaneous casting doesn't seem to be as useful as the long-term versatility granted by an unrestricted spellbook, and the sorcerer's apparent increase in spells per day isn't really all that much when compared to a specialist wizard.
I am assuming that arcane casters overall have been weakened, such as through
my wizard fix; this is meant to then get them back up to the level of the new wizards.
1. Sorcerers get Use Magic Device as a class skill. (Rationale: Due to the inability to specialize and having access to the biggest spell list, sorcerers will naturally be good for wand/scroll use. This takes that ability one step further, and fits well with their CHA focus.)
2. Class feature (level 1): Magical intuition (Su). Sorcerers may use Charisma, rather than Intelligence, as the key ability score for Spellcraft.
3. Class feature (level 5): Magic surge (Su). A sorcerer may cast any spell with a Magic Surge. This increases the casting time to 1 round (or increases the casting time by 1 round if it had previously been at least 1 round), but allows the sorcerer to add half his Charisma bonus to all caster level checks and dispel checks associated with the spell.
4. Class feature (level 10): Above and beyond (Su). A sorcerer may, as a free action, increase his caster level by a number up to his charisma bonus for 1 minute per point of charisma bonus. This costs experience equal to 100 XP times the number of levels increase times the new caster level. (Rationale: This allows the sorcerer to get the occasional boost for special occasions, allowing him to cast from scrolls substantially beyond his level or to be an even better dispeller.)
5. Class feature (level 15): Greater magic surge (Su). When using Magic surge, a sorcerer may increase the casting time by another round to add his full charisma bonus instead of only half.
6. A sorcerer gains extra spells known from a high charisma score just as he gains extra spells per day, but only ability modifiers that affect skill point gain (as per PHB p.58) affect these extra spells known.
The result is a very volatile class, who is weaker than the wizard in most situations but if he's willing to spend the resources can be quite powerful and versatile. (He's also great for dispelling tough spells out of combat.)
Thoughts?