You're building a "custom content" server...

[Secrets]

Custom content ideas:

-AOE Cone Spells. EQ is distinctly missing rangers being able to expel an AOE cone of arrows or a wizard blasting with an AOE snare of frost on a short cast time.
-Channeled Spells - Long DoT spells with different effects. For example, Necromancers could siphon life, enchanters could siphon mana over time. Ticks for channeled spells would be once per second. Could be interrupted with duck.
-Sentinel-style spells that provide AOE benefits/detriments to the group when triggered. Example, a rogue/ranger can plant tradeskilled traps for NPCs to trigger.