Responding to this very old thread just for a place to put my thoughts down ... This is how I would make different kinds of magic FEEL different within the mechanics of the game.
Arcane Magic:
No more spell slots for Wizards. Arcane magic by a wizard is a learned process. Instead, Arcana...
Some pieces I would add into my game:
Better monster design, specifically around
more spell-like effects rather than spell so that players can't just shut down everything with counterspell.
more templates so that DMs don't feel hamstrung around how a monster is presented but are more open to...