Here you find my Carrilion Campaign Setting rules for fantasy roleplaying.
Changing the table to grant bonus zero-level spells is one possible solution well suited for standard campaigns. They would simply be aquired one 'row' earlier:
|Bonus Spells (by Spell Level)|
|1||-5||Can't cast spells tied to this ability|
|2-3||4||Can't cast spells tied to this ability|
|45||3||Can't cast spells tied to this ability|
|67||2||Can't cast spells tied to this ability|
|89||1||Can't cast spells tied to this ability|
|etc. . .|
In a campaign where magic is more common - like Carrilion - a number of bonus zero-level spells equal to the ability score modifier could be granted. This house rule has been proposed by Keith Davies on rec.games.frp.dnd, see the Links page.
The rare gnomes live in the faerie realms and almost never travel to the world of humans.
Halflings, orcs and half-orcs don't exist on Carrilion.
And playtesting at the moment: the Martial Magician - a fighting arcane caster. He gets along so far - in a party of four PCs with a Druid, a Rogue and a Priestess of Boand.
The positive and negative elemental planes don't exist and are completely unknown on Carrilion. There are only four elements discerned: Earth, Water, Air, and Fire.
More information will be made available when I've got the time.
Armor: Splint mail and full plate armor, as well as armor and shield spikes are unknown. Only dwarven smiths know how to make breastplate and half-plate armor. They don't sell these armors to everybody, the only non-dwarfs who may buy such armor normally are knights of the Holy Order of the Silver Dragon (the Paladins of Carrilion), because the order has a kind of secret treaty with the dwarven kingdom of Isenmark as rumour has it...
Conclusion: Banded mail without armor spikes is the only common heavy armor for non-dwarven low-level characters. Dwarves and Paladins may have a breastplate or a half-plate armor without armor spikes, if they can afford it.
The new and variant monsters of Carrilion currently hide among the paper notes in various more or less dusty folders on the shelves in my chamber.
Monsters of the elemental, ooze and outsider type are very rare and not a normal part of the Carrilion "ecology".
Final note: I don't use a monster in my Carrilion Campaign, if it looks like the doodle of a toddler who tried to draw an octopus - it would offend my aesthetic sensibilities. On Carrilion there are no ropers, carrion crawlers, otyughs or phantom fungi (shudder)...