Would you like to play as a Necromancer with the ability to upgrade Vampires?

What's wrong with the idea of limiting basic spells?

For example, even at level 2 (on one of the first levels), you'll be offered Eagle Eye or Advanced Necromancy – and what then?

That's just bad luck; either level up Eagle Eye or switch to another hero. But Necromancer is already promising.

Limiting basic spells is essentially the same as the Necromancer patch.