I can't see any immediate problems with it. Is here a reason for restricting the spell class?


One thing I might be tempted to do as an alternative is make it Enlarge/Reduce and a spell that corresponds to Giant type? The elf magic feats can give spells up to 3rd level so you could push it a bit higher.

Fog Cloud, Heat Metal, Spike Growth, Maximillian's earthen grasp, Earthbind, levitate...