Since the spell roll is based on level the spell success gets higher for each level a character attains. This makes me think that spells themselves don't need levels. Higher level caster will get more out of a spell usually.
I started doing this last week as part of my DCC and C&C integration. I'm taking a line from Savage Worlds, and making generic classes of spells, for instance, Detect is a spell class with three variations -- haven't decided whether the wizard learns "Detect" and then perfects the three variations ( by some other mechanic or if I'm just organizing... But anyway, Results vary by the Spell check roll. Anyway, the variations are Physical Features, Alchemical Properties and Magical Properties. This lumps in (on the physical side) Secret doors and traps, (on the alchemical side) poison and identify (just for potions), and (on the magical side) general magic, specific magic and identify for all other magical things.
For magic missile, fireball, etc etc, I'm going to either use the "Bolt," "Blast," etc, etc method of Savage Worlds, or call it Elemental Control, and have a variation that allows various forms of magical missiles, explosions, etc. With an added CL to the spell check for various energies to tack on.
I'm taking the approach of doing more with less spells. I've even considered making clerics and wizards essentially the same -- with the only difference being that the cleric derives his power more directly than a wizard... dunno. Still thinking about that.
I'm going to play with this and see how it works, but seemed to work great in Savage Worlds. In addition, it seemed to give the DM better control over what a spell actually does -- meaning the player (and the character) don't know what to expect.