(suggestion)
Maybe it is intended in this way, but currently the only ways to increase the damage of the spell are wearing that full armor set or making it in the mortar by adding glowstone.
Anyways, I think it would be great that the damage of the abilities scales as "magic" damage. Like, for example, the damage that comes from the potions. Mods like Eidolon (with it's Soulfire wand), Savage&Ravage (with the Iceologer Wand), Mowzie's Mobs (with the Ice Crystal, dropped from the Frostmaw), or the Omnis mod (with the Spellblades) have weapons or artifacts that deals magic damage, and there are some ways to improve it: Eidolon has a full Warlock set, being the Hat the one that increases the magic damage. Omnis has the Evoker Charm (dropped by Evokers, of course) and a Magic Proficiency potion; which both increases magic damage. Wearing the hat, the Evoker Charm and having this potion, you can increase the damage from the Soulfire Wand from 7 to 21.
As I said, maybe you've already contemplated this idea, and want that the only way to increase the damage of the spells that does damage is the ones from the mod; or maybe it would be too hard to code that as "Magic" damage and could break any of the mod.
But, if this are not the cases, it would be really nice to have this addition; inciting even more an RPG system with a Druid class, which you combine Charms from different mods to have more power.
Hope you like my suggestion!