So, my biggest problem with magic right now is the state it will be in at launch (persistence). It will only have ecumenical (magic for beginners, as Henrik kinda explains it), and spiritism, which I kinda explained my thoughts on that in further comments. Basically, it's a new game within the game, that hardly adds more to the overworld experience. If spiritism offered just the slightest more utility as a support class, I'd have a lot less to complain about. The unfun (because boring is boring, this is a little irritating) way you have to farm spirits in a grind that leaves little benefit to your experience, just isn't quite worth it to me.
It can be something small, like a summonable magelight (spirit lantern) for dungeons, or a spirit armor spell that temporarily boosts armor class for people with low armor weight. Just grinding your way up the skills only for the resurrection ability, spending upwards to 200 skill points, is kinda unfulfilling to me.
But with the little mini game that is exorcising spirits, it's pretty annoying... Doing a ghost busting siphon ray on tiny orbs that rotate around the target, and its rays look just like yours is kinda messy design. I would rather see a spirit like a human soul attacking as though they think theyre alive, and each attack drains kau. Your spells/abilities would be to defend against them, and ultimately banish them. But that's just an opinion.