I think you are worrying too much.
In Beta 3C it seemed that PLENTY spells needed shards. And while I can't speak for Beta 4 (yet) ... Its my impression that the more powerful 10-25% of the spells should require shards ... and most of the rest of the spells have a "cheaper, more cost effective counterpart" that requires a shard.
So for instance ... "Flare" could deal 3-5 fire damage to a 1-tile radius using a 10 tile range and require 6 mana
While "Fireball" could deal Int/2 <-> Int*2 fire damage to a 1-tile radius using a 15 tile range and require a fire shard + 5 mana
This way, it would still be *possible* to play the magician without a shard "for a time" but far less feasible.
This makes more sense to me, and is similar to using "soft caps"