I'm not sure how to make this into a viable option as of now, but I'm considering the Multiclass feats for the 0th level: they represent what makes those classes "tick". Maybe something like, half everything (hp, surges, etc) plus the benefits of the multiclass feat for the class you'll pick at first level. No second wind.
So an aprentice wizard would have 10hp, 3 surges, the Arcana skill and could cast Force Orb once per encounter.
I thought about extending this into an Novice Tier, but I suppose it would be too complicated for little gain: as a player, I usually want the "I suck" levels to end as soon as possible.