I wonder why people fixate so much on the filler parts of a rotation. Does it really matter if you're slowly rolling your face across the keyboard or banging your forehead against a single key at baseline? The meat of the gameplay of a job comes out of its cooldowns and resource management. Take that away and they are all equally boring. That's what your focus should be on.

It's easy enough to create a magic-themed version of the filler combos that melee jobs use. All you need is a few more DoTs to juggle. If you want to make it a bit more challenging, have every additional DoT cast on a target increase the potencies and reduce the timers on all of the other active DoTs. The main issue with DoTs and DoT timers is that newer players get intimidated by them, and they don't really add much in the way of complexity once you become more comfortable with a job. The filler stuff just becomes muscle memory over time.